JP2009272561A - Surface light emission type semiconductor laser device and method of driving same, optical scanning optical system, and image forming apparatus using them - Google Patents

Abstract

In a semiconductor laser (LD) having a plurality of emission channels, a method for controlling the temperature of individual emission channels has not been put into practical use. When temperature control is performed by providing a temperature sensor on an LD substrate, the overall average temperature can be controlled, but individual light emitting channels cannot be controlled. In particular, in the case of a high-density LD array used for an image forming apparatus or the like, the driving load of the light emitting channel does not always occur uniformly, and individual heat generation variations tend to increase.
A pillar as a temperature adjusting unit is provided in the vicinity of a pillar type light emitting channel to absorb radiant heat from the light emitting channel whose temperature has increased. The heat absorbed by the temperature adjusting unit is radiated from the temperature adjusting unit and dissipated. In the case of a configuration in which the temperature of the light emitting channel is too low and unevenness in the amount of light is a problem, the temperature adjusting unit itself can be configured to generate heat by current injection, and can be controlled to a substantially constant temperature at all times. The temperature adjustment unit can be configured similarly to the light emitting channel.
[Selection] Figure 10

Description

  The present invention relates to a surface-emitting type semiconductor laser device having a plurality of emission channels. In particular, the present invention relates to a laser device capable of avoiding or reducing change or disappearance of bistable characteristics due to temperature fluctuations of a polarization bistable surface emitting semiconductor laser that exhibits optical bistability and is capable of polarization switching operation, and a driving method thereof.

It is well known that semiconductor lasers vary in oscillation wavelength and oscillation mode due to expansion and contraction of the laser cavity length and generation of distortion due to temperature fluctuations. Feedback control based on detection signals from temperature sensors, optical power monitors, etc. Often used in conjunction with stabilization measures.
Further, attention is paid to the fact that optical bistability is exhibited in a semiconductor laser, and application of high-speed switching operation of polarization characteristics to optical communication has been studied (for example, see Patent Document 1). When optical bistability is exhibited, a hysteresis characteristic appears in the relationship between the injection current and the oscillation light intensity, and a hysteresis loop characteristic is exhibited. It is known that this hysteresis loop characteristic has temperature dependence, and when the temperature exceeds a predetermined temperature range, the hysteresis loop characteristic disappears. From this, it is recognized that temperature control is important for stable operation of ultrafast switching using optical bistability (see, for example, Patent Document 2 and Patent Document 3).

In recent years, studies have been made on increasing the number of channels of optical communication and increasing the capacity and speed by using a surface emitting semiconductor laser array in which the light emitting surfaces can be integrated on the same surface. Alternatively, in an optical writing apparatus, high-speed and high-density writing is being realized by a surface emitting semiconductor laser array (see, for example, Non-Patent Document 1).
FIG. 1 of Non-Patent Document 1 shows the relationship between the active layer temperature of the polarization bistable laser and the hysteresis loop. When the temperature is out of the predetermined temperature range, the hysteresis loop characteristic disappears. In the hysteresis loop, when the temperature of the active layer increases, polarization switching occurs on the side where the injection current is low, and when the temperature of the active layer decreases, the polarization switches on the side where the injection current is high.
The surface-emitting semiconductor laser (VCSEL) also includes a surface-emitting semiconductor laser exhibiting polarization bistability. By using this, it is expected to realize multi-channel ultrafast polarization bistable switching. Even in this case, it is important to maintain the temperature of the VCSEL stably in order to maintain the polarization bistability satisfactorily. In addition, when the light emitting element has an array structure like VCSEL, it is important to make the light emission characteristics uniform between the channels.
The present invention particularly relates to temperature control of a VCSEL (see, for example, Patent Document 4) formed in a pillar structure.

Japanese Patent Publication No. 6-40595 Japanese Patent Laid-Open No. 1-215078 JP 2007-48905 A Japanese Patent Laid-Open No. 2005-45243 Y.C.Chen and J.M.Liu, Switching mechanism in polarization-stable semiconductor lasers, Optical and Quantum Electronics, Springer Netherlannds, July 1987, Vol. 19, S93-S102

Although a method for stabilizing the overall temperature of the device by means of a temperature sensor, a Peltier device, or a feedback circuit has been shown for these important issues, in this type of device having a multi-channel structure, A method for individually controlling the temperature of the light emitting channel and making the temperature difference between the channels uniform has not been shown.
In view of the above background, an object of the present invention is to independently control the temperature of each light emitting channel in a surface emitting semiconductor laser and to suppress temperature variation between channels.

According to the first aspect of the present invention, there is provided a surface emitting semiconductor laser device having a plurality of light emitting channels used for generating an optical signal, the temperature of which is adjusted for one light emitting channel or a plurality of light emitting channels. One or more temperature adjusting units are provided, and when the temperature of the temperature adjusting unit is lower than the temperature of the light emitting channel, the temperature adjusting unit absorbs heat of the light emitting channel.
According to a second aspect of the present invention, in the surface-emitting type semiconductor laser device according to the first aspect, the temperature adjusting unit has a configuration capable of injecting a current, and the temperature is adjusted by injecting the current into the temperature adjusting unit. The temperature of the light emitting channel can be increased by increasing the temperature of the adjusting unit and by the heat of the temperature adjusting unit.
According to a third aspect of the present invention, in the surface-emitting type semiconductor laser device according to the first or second aspect, the temperature adjusting unit is a channel having a function equivalent to that of the light emitting channel (hereinafter referred to as a main channel). For the sake of convenience, this will be referred to as a sub-channel).
According to a fourth aspect of the present invention, in the surface-emitting type semiconductor laser device according to any one of the first to third aspects, a plurality of temperature control units correspond to positions where the temperature can be controlled with respect to one light emitting channel. It is characterized by being attached.

According to a fifth aspect of the present invention, in the surface-emitting type semiconductor laser device according to any one of the first to fourth aspects, the number of temperature control units for one emission channel is greater than that of a peripheral part in the channel arrangement plane. Is also characterized by the fact that there are many more in the center.
According to a sixth aspect of the present invention, in the surface-emitting type semiconductor laser device according to any one of the first to fifth aspects, the interval between the light emitting channels is greater in the central portion than in the peripheral portion in the channel arrangement plane. It is characterized by being widely arranged.
According to a seventh aspect of the present invention, in the surface-emitting type semiconductor laser device according to any one of the first to sixth aspects, the central portion is located in the central portion rather than the peripheral portion in the channel array plane. It is characterized in that the volume is increased.

According to an eighth aspect of the present invention, in the surface-emitting type semiconductor laser device according to any one of the first to seventh aspects, the central portion is exposed to the temperature adjustment portion rather than the peripheral portion in the channel array plane. It is characterized by having a large surface area.
According to a ninth aspect of the present invention, in the surface-emitting type semiconductor laser device according to any one of the first to eighth aspects, the temperature adjusting unit has a function as a radiating fin.
According to a tenth aspect of the present invention, in the surface-emitting type semiconductor laser device according to any one of the first to ninth aspects, the temperature of the light emitting channel is controlled for one or more light emitting channels. Two or more temperature control units are associated with each other.
According to an eleventh aspect of the present invention, in the surface emitting semiconductor laser device according to any one of the first to tenth aspects, the surface emitting semiconductor laser device is a polarization bistable type.

According to a twelfth aspect of the invention, there is provided a driving method for driving the surface emitting semiconductor laser device according to any one of the third to tenth aspects, wherein the main channel is moved from the main channel at a predetermined timing. The light emission mode is switched to the sub channel, the main channel is set to the non-light emission mode, the light emission mode is switched from the sub channel to the main channel at another predetermined timing, and the sub channel is set to the non light emission mode. It is characterized by that.
According to a thirteenth aspect of the present invention, in the driving method for driving the surface-emitting type semiconductor laser device according to the twelfth aspect, the channel in the non-light emitting mode functions as a temperature control unit.
According to a fourteenth aspect of the present invention, in the driving method for driving the surface-emitting type semiconductor laser device according to the thirteenth aspect, an amount of current per unit time injected into the channel of the temperature adjusting unit is in the light emission mode. The channel is driven so that the light emission time is reduced when the light emission time is long, and the light emission time is increased when the light emission time is long.
According to a fifteenth aspect of the present invention, in the method for driving a surface-emitting type semiconductor laser device according to the thirteenth or fourteenth aspect, the channel of the temperature adjusting unit is an injection current independently for each channel in the corresponding light emission mode. The amount is controlled.

According to a sixteenth aspect of the present invention, in the method for driving a surface-emitting type semiconductor laser device according to any one of the thirteenth to fifteenth aspects, a time for injecting a current into the channel of the temperature adjusting unit is in the light emission mode. It is characterized in that it is driven so that the light emission time of a certain channel is short when the light emission time is long, and is long when the non-light emission time is long.
According to a seventeenth aspect of the present invention, in the method for driving a surface emitting semiconductor laser device according to the sixteenth aspect, the channel of the temperature adjusting unit controls the current injection time independently for each channel in the corresponding emission mode. It is characterized by being.
According to an eighteenth aspect of the present invention, in the method for driving a surface emitting semiconductor laser device according to any one of the thirteenth to fifteenth aspects, the temperature when the channel in the light emission mode emits light or does not emit light. When the currents to be injected into the channel of the adjustment unit are Ion and Ioff, currents are injected so that Ion <Ioff.
According to a nineteenth aspect of the present invention, in the surface emitting semiconductor laser device driving method according to any one of the thirteenth to eighteenth aspects, the number of channels used for temperature control when there are a plurality of temperature control unit channels Are selectively driven so as to increase when the temperature difference between the channel in the light emission mode and the channel used for temperature control is large.
According to a twentieth aspect of the present invention, in the driving method of a surface emitting semiconductor laser device according to any one of the twelfth to nineteenth aspects, the surface emitting semiconductor laser is a polarization bistable type. To do.
In a twenty-first aspect of the present invention, in the optical scanning device having a light source, an optical scanning unit, and an imaging optical system, the light source is the surface emitting semiconductor laser according to any one of the first to eleventh aspects. It is a device.
According to a twenty-second aspect of the present invention, in the image forming apparatus including at least an optical scanning optical device, a plurality of photosensitive members, a developing device, and a transfer device, the optical scanning optical device is the optical scanning according to the twenty-first aspect. It is an optical device.

  According to the present invention, the temperature of the light emitting channel can be individually controlled for each channel. Thereby, temperature variation between channels and emission characteristic variation between channels can be reduced.

FIG. 1 is a diagram for explaining an embodiment of the present invention. FIG. 4A is a plan view of a surface emitting semiconductor laser arranged in a two-dimensional array, and FIG. 4B is a schematic plan view showing a configuration in which light emitting channels and temperature adjusting units are arranged in a one-to-one relationship. FIG. 4C is a side view thereof, FIG. 4D is a schematic plan view of a configuration in which a plurality of temperature adjustment units correspond to one light emitting channel, and FIG. It is a plane schematic diagram of the structure which a temperature control part respond | corresponds.
In the figure, reference numeral 1 denotes a light emitting channel, and 2 denotes a thick pillar.
The circular portion of the light emitting channel 1 shows the outer shape, and the inner rectangle shows the opening for laser oscillation.
FIG. 2 is a diagram showing a configuration with improved heat dissipation.
In the figure, reference numeral 3 denotes a thin pillar.
In the embodiment of the present invention, in a surface emitting semiconductor laser in which light emitting channels are arranged in a one-dimensional (not shown) or two-dimensional array shown in FIG. Is provided. Since the temperature adjustment mechanism can be variously modified as shown below, the temperature adjustment mechanism is omitted in the figure. An example of the structure of the temperature control mechanism is a pillar structure. The pillar structure refers to a structure extending in a columnar shape with respect to the surface, and can be formed as a periodic assembly depending on the configuration conditions.

This pillar structure can take any shape and number depending on the temperature control specifications. FIG. 2B shows an example in which light emission channels and pillars (hereinafter referred to as temperature adjusting units) as temperature adjusting mechanisms are associated one-to-one. In this figure, the light emission channel and the temperature control unit are basically cylindrical. In the figure, in order to avoid complexity, only one set of the light emitting channel and the temperature control unit corresponding thereto is displayed, and the substrate is omitted. The light emitting channel 1 inevitably generates heat as the laser light is emitted. If the temperature of the light emitting channel rises too much due to this heat, it is impossible to emit light as planned, so it is necessary not to exceed a predetermined temperature range. By providing the temperature adjusting portion in the vicinity of the light emitting channel, the radiant heat emitted from the cylindrical body of the light emitting channel 1 is absorbed by the temperature adjusting portion having a temperature lower than that of the light emitting channel, and the light emitting channel is also generated by the conduction heat through the substrate. The heat is absorbed by the temperature control unit.
A light emitter array is formed by arranging a plurality of such combinations of the light emitting channel and the temperature control unit shown in FIG. If the array has a one-dimensional configuration, it can be configured, for example, by arranging a plurality of sets in the figure in the vertical direction of the figure.

FIG. 4D shows a configuration in which four temperature control units are associated with one light-emitting channel, but the number is not limited to four, and there are three even if there are two. It doesn't matter. However, as described later, it is desirable that the temperature control is as symmetric as possible with respect to the light emission channel. Therefore, when there is one light emission channel, it is preferable that the temperature control be symmetrical with respect to the light emission channel. Also in this figure, the substrate is omitted. Also in each of the following drawings, the description of the substrate is omitted when only the arrangement of the light emitting channel and the temperature control unit is shown.
FIG. 4E shows an example in which one temperature adjustment unit is provided for two light emitting channels. However, it can be used only when the temperature control of these two light emitting channels can be performed at the same time. It is a configuration.

  The larger the volume of the temperature control unit, the greater the heat capacity, and the better the heat absorption from the light emitting channel. However, if the heat capacity is simply large, the heat dissipation efficiency is lowered, and the response characteristic of the temperature control is delayed. In order to improve the heat dissipation effect and its responsiveness, a shape with a large surface area has an advantage. For example, compared to the case of providing one thick pillar, by providing a large number of thin pillars as shown in FIG. 2, it is possible to achieve both heat dissipation, heat absorption, and temperature control responsiveness. is there. In order to increase the surface area, it is also effective to make the shape of the temperature control portion a fin structure.

By providing a means for injecting current into the pillar structure, it is possible to give the pillar structure a function as a heater and to control to raise the lowered temperature.
Since the temperature control unit is basically formed in the same process as the light emission channel, the temperature control unit and the light emission channel can be separately formed by a mask used in the process. Since the light emitting channel is provided with an electrode structure, the temperature adjusting portion can be similarly provided with an electrode structure. If two electrodes are formed in the vertical direction of the pillar structure and a resistor is formed between them, Heat can be generated by energizing both electrodes.

FIG. 3 is a diagram for explaining another embodiment.
In the figure, reference numeral 2 'denotes a temperature control unit, 4 denotes a side surface of the light emitting channel, and 5 denotes a side surface facing the light emitting channel of the pillar structure.
In the semiconductor laser device, heat radiated from the structure side surface 4 of the light emitting channel 1 serving as a main heating element is absorbed by the surface facing the light emitting channel 1 of the temperature adjusting unit 2 ′. From the viewpoint of absorption efficiency, in particular, when the light emitting channel 1 has a cylindrical pillar shape, it is recognized that there is an advantage in providing a curved surface shape 5 that follows the side surface 4 thereof. In the figure, the side surface 5 of the pillar structure facing the light emission channel 1 has a shape that follows the shape of the side surface 4 of the light emission channel. Such a side shape is a preferable form in terms of absorption of radiant heat.

FIG. 4 is a schematic diagram showing a temperature change of the light emitting channel due to current injection into the temperature adjusting unit.
In the figure, reference numeral 6 denotes a waveform of an injection current signal to the temperature control unit, 7 denotes a temperature variation of the temperature control unit, and 8 denotes a temperature variation when the light emitting channel is not emitting light. Hereinafter, the temperature control unit is represented by reference numeral 2.
The temperature control unit 2 can be configured to allow current injection as described above. With this configuration, the temperature control unit can be provided with not only a function of merely absorbing heat but also a function of generating heat. When the input signal of the light emitting channel is small, if the temperature of the light emitting channel is too low due to natural heat dissipation, output fluctuation occurs compared to when there is a continuous input signal. It is necessary to positively increase the temperature. This function makes it possible to keep the temperature of the light emitting channel substantially constant, so that it is not necessary to worry about output fluctuations.
Heat generated by current injection into these temperature control units is transmitted to the adjacent light emitting channel side by radiation and conduction through the substrate, and the temperature of the light emitting channel is raised accordingly. When the amount of current injected into the temperature adjustment unit is reduced, the temperature increase of the temperature adjustment unit is mitigated, and the contribution to the temperature increase of the light emitting channel is also reduced. When current is not injected, heat dissipation becomes dominant and the temperature of the temperature adjusting mechanism starts to decrease. In the present invention, the temperature control pattern by adjusting the injection current can be given free selectivity according to the state.

FIG. 5 is a diagram for explaining another embodiment.
In the figure, reference numeral 9 denotes a light emission channel, and 10 denotes a temperature control unit.
In order to increase the heat dissipation efficiency of the temperature control mechanism, it is most convenient that the structure preferable as the temperature control unit is the same regardless of the position of the light emitting channel. In the figure, the light emitting channel 9 and the temperature adjusting unit 10 have the same shape.

FIG. 6 is a diagram for explaining another embodiment.
In the figure, reference numeral 11 denotes a light emitting channel at a channel position where heat is not easily radiated on the channel substrate, and 12 denotes a temperature adjusting unit.
FIG. 7 is a diagram for explaining another embodiment.
In the drawing, reference numeral 13 denotes a light emitting channel at a channel position where heat is easily radiated on the channel substrate, and reference numeral 14 denotes a temperature adjusting unit.
In particular, considering that the heat dissipation characteristics differ depending on the position of the channels forming the array arrangement on the channel substrate, it is preferable that the arrangement as the temperature adjusting unit is also devised correspondingly, for example, it is difficult to dissipate heat. It is useful to take an arrangement with high heat dissipation at the channel position.
As shown in FIG. 6, the number of the temperature control units 12 is increased at channel positions where heat is not easily radiated (for example, the periphery in the channel arrangement plane), and conversely, channel positions where heat is apt to be radiated as shown in FIG. In the peripheral part in the channel arrangement plane, the number of temperature control parts 14 is reduced.

In order to improve heat dissipation, it is preferable to increase the total surface area by increasing the number of pillar structures.
Alternatively, a metal material having good heat conduction characteristics is effectively selected. For example, Al is suitable. Further, from the viewpoint of the absorption efficiency of radiant heat, it is preferable that the surface reflectance is low and that it is blackened. This also improves the absorption efficiency of radiant heat from the light emitting channel.

FIG. 8 is a view for explaining a pillar structure with improved heat absorption efficiency.
In the figure, reference numeral 15 denotes a stacked structure of VCSELs, 16 denotes a side surface of the VCSEL, 17 denotes a pillar structure, 18 denotes the height of the VCSEL, and 19 denotes the height of the pillar structure.
In contrast to the VCSEL laminate structure 15 mainly having a cylindrical shape, a specially shaped pillar structure 17 having a structure that at least partially surrounds the side face 16 also increases the absorption efficiency of the radiant heat from the laminate structure, The thermal adjustment effect can be enhanced.

  The height 19 in such a pillar structure is configured to substantially coincide with the height 18 of the VCSEL light emitting unit laminated structure 15, so that an optical element such as a light receiving element or a microlens that receives light emitted from the VCSEL is used. It is preferable in view of the arrangement configuration with the element modules.

The VCSEL light emitting unit laminated structure 15 is arranged in close contact with a predetermined gap, and can take a configuration that surrounds the VCSEL light emitting unit laminated structure 15. It is possible to easily construct the pillar structure shown on the left with respect to each of the plurality of VCSEL channels by using a mask process.
The present invention is not limited to the pillar having the structural characteristics exemplified above.

It is also possible to adjust the temperature independently for each of the light emitting channels using the pillar structure. As already described, the current injection means is provided to the pillar structure, and by selecting the pillar for injecting the current, the light emitting channel that gives the thermal control action can be selected.
The light emitting channel shown in FIGS. 1 to 7 may also be a VCSEL stacked structure.

FIG. 9 is a schematic diagram showing the direction of current injection.
In order to give a uniform thermal control action in the entire VCSEL stacking direction, it is desirable that the current injection is conducted in the pillar height direction (Z direction) as shown in FIG.

Even when the resistance value of the pillar itself is high, the entire pillar can be uniformly heated by embedding the thin electrode wire 20 in the Z direction in the center of the pillar.
The present invention is not limited to the current injection means exemplified above.

In the above embodiment, a temperature adjustment mechanism that is not the same as that of the light emission channel is provided, but the element configuration and the manufacturing process are greatly increased by the idea that a part of the plurality of light emission channels of the VCSEL is used for temperature adjustment. Can be facilitated.
Here, a channel used for light emission is referred to as a main channel, and a channel used for temperature adjustment is referred to herein as a sub channel. The subchannel may have the same structure as the main channel, and can be formed simultaneously with the main channel. The secondary channel can also have the same diameter, height and volume as the main channel. When the two are collectively referred to without distinguishing between the main channel and the sub channel, they may be simply referred to as a channel.

FIG. 10 is a diagram for explaining another embodiment.
In the figure, reference numeral 21 is a main channel, 22 is a subchannel, 23 is the height of the main channel, and 24 is the height of the subchannel.
This figure is a perspective view corresponding to a configuration in which the temperature adjusting unit in the arrangement shown in FIG. 2 is replaced with a sub-channel.
It is also possible to make the diameter of the secondary channel 22 different from that of the main channel 21. Further, the shape of the cross section is not limited to a circular shape, and the shape of the cross section is not limited to the shape shown in FIGS.
It is preferable that the height 23 of the main channel and the height 24 of the subchannel are substantially equal from the viewpoint that the thermal interaction between the main channel and the subchannel can reach the entire laminated structure.

Since the subchannel 22 is manufactured by the same process as the main channel 21 and can have the same function, it is also possible to inject current in the same way as the main channel. Therefore, temperature control is performed by a current injection control method. Is a very natural and efficient choice. By injecting current into the subchannel, heat generated in the subchannel can be transferred to the adjacent main channel. Therefore, when the temperature of the main channel is lower than a desired range, the temperature is controlled to increase. be able to.
Since the basic structure of the subchannel is the same as that of the main channel, the subchannel also emits light when a current of the same level as the injection current necessary for light emission of the main channel is injected. Therefore, when a current is injected into the subchannel for the purpose of increasing the temperature, it must be injected within a current value range below the threshold level for starting oscillation of the subchannel.
Note that the present invention is not limited to the subchannels exemplified above.

Further, when current injection into the subchannel is not performed, the subchannel functions as a temperature absorbing portion and absorbs or dissipates heat generated in the main channel. When the secondary channel is used for temperature adjustment, the secondary channel is called a temperature adjustment unit.
It is preferable that there is at least one subchannel around the main channel of interest.

FIG. 11 is a diagram for explaining another embodiment.
In the figure, reference numeral 25 denotes a main channel and 26 denotes a sub channel.
Depending on the specification purpose of temperature control, a plurality of sub-channels 26 can be associated with one main channel 25 as shown in FIG.
In this configuration, one subchannel faces a plurality of main channels depending on the location. Therefore, which subchannel current injection amount is controlled depends on the temperature difference between the main channel and the subchannel. Determined by reference. For example, if the main channel emission time is long, the temperature tends to rise, so even if the temperature is not directly measured, the temperature rise is estimated from the product of the injection current and the injection time, and the subchannel to be controlled is selected. The injection current can be controlled.

FIG. 12 is a side view of the VCSEL array.
In the figure, reference numeral 27 denotes a light emitting surface.
FIGS. 13, 14 and 15 are diagrams showing examples of arrangement of sub-channels with respect to the main channel.
FIG. 13 shows an example in which the top, bottom, left and right of the figure are arranged symmetrically. FIG. 4A is a diagram showing an arrangement when attention is paid to one main channel, and FIG. 4B is a diagram showing a configuration example when arranging a plurality of main channels.
FIG. 14 is a diagram for explaining the configuration when the oscillation direction is set in a diagonal direction with respect to the arrangement direction of the main channels. FIGS. 9A and 9B are the same as those in FIG. FIG. 11B is the same form as FIG.
FIG. 15 is a diagram showing an example in which the sub-channels are arranged so as to be concentrically symmetrical with respect to the main channel. FIG. 5A is a diagram showing an arrangement when attention is paid to one main channel, and FIG. 5B is a diagram showing a configuration when a plurality of main channels are arranged.
In each figure, reference numeral 28 indicates a main channel, and 29 indicates a sub-channel.

In consideration of the symmetry of the temperature distribution in the light emitting surface 27 in the VCSEL array, the subchannel 29 is arranged so that the temperature distribution in the upper and lower (Y direction) and left and right (X direction) in FIG. Or symmetrically arrange the subchannels so that the diagonal directions are symmetrical as shown in FIG. 14 or symmetrically arrange the subchannels so as to be concentrically symmetrical (FIG. 15), The effect of improving the symmetry of the temperature distribution can be enhanced. By increasing the symmetry of the temperature distribution, it is possible to avoid the occurrence of asymmetric distortion in the device due to heat and its distribution, so that it is effective in maintaining stable polarization bistability and oscillation An effect on mode stability is also obtained.
The configuration shown in FIG. 15 is an example in which the diagonal direction is arranged symmetrically in addition to the vertical and horizontal directions, but the present invention is not limited to the sub-channel arrangement pattern exemplified above. For example, the arrangement shown in FIG. 16 is also possible as another example in which the diagonal direction is arranged symmetrically in addition to the vertical and horizontal directions. The configuration shown in FIGS. 15 and 16 is excellent in that the temperature control can be performed independently for each main channel because the sub-channel surrounding the main channel is not adjacent to the other main channels.

Even if such temperature control by the sub-channel is performed, it is assumed that the temperature of the main channel significantly increases due to a very specific optical signal train or the like. However, even in such a case, since the secondary channel also has an optical signal generation function, the secondary channel and the primary channel can be used interchangeably. This is particularly effective when the temperature of the secondary channel is lower than the temperature of the main channel. In the case of this application, since all channels can be light emission channels, the distinction between the main channel and the sub channel is meaningless, but the representation of the main channel and the sub channel is used for convenience.
In the case of a light source for use in an image forming apparatus, the image writing position is shifted by the arrangement position of both channels by switching the main channel and the sub channel to emit light. To avoid this problem, make sure that all secondary channels are in the same relative relationship with the corresponding main channel, and if any of the emission channels is about to exceed the specified temperature, It is desirable to switch all the light emitting channels simultaneously. By doing so, since the above-mentioned positional deviations are all the same, the optical deviation can be easily corrected. Depending on the configuration, the positional deviation can be corrected only by adjusting the write timing.

When there are a plurality of sub-channels for one main channel, it is preferable to switch the sub-channel used for switching to a sub-channel that is in a specific positional relationship with the main channel.
In the case of the arrangement shown in FIG. 16, all the currently emitting channels can be simultaneously switched to one of the upper, lower, left, and right subchannels, for example, switching in order of up, right, down, and left. As a result, sufficient time can be taken for the temperature drop. In this case, for example, the positional deviation of the light emitting channel may be optically corrected when switching up and down, and the writing timing may be corrected electrically when switching between left and right.
When there are multiple sub-channels for one main channel, the number of channels used for temperature control is selectively driven so as to increase when the temperature difference between the channel in the emission mode and the channel used for temperature control is large. May be.

FIG. 17 is a diagram for explaining an example of switching input signals of the main channel and the sub channel.
In the figure, reference symbol Ith indicates a threshold value of an injection current leading to the start of light emission of the VCSEL.
The light emission mode and the non-light emission mode of the main channel 28 and the sub channel 29 are switched. The timing for switching can be determined as appropriate, such as estimating a temperature rise based on the operation history of the main channel. When the light emission mode is set, a signal such as image data is input. When the non-light emission mode is set, a temperature adjustment input is made.
When the main channel is in the light emission mode, a current Ioff equal to or lower than the threshold current Ith is given to the subchannel in the non-light emission time zone of the main channel. Conversely, when the subchannel is in the light emission mode, a current equal to or smaller than the threshold current Ith is applied to the main channel during the non-light emission time period of the subchannel. By doing in this way, the temperature fluctuation of the channel in the light emission mode can be suppressed to be small. In this example, the channel on the side not in the light emission mode functions as a temperature controller. In the figure, when the channel in the light emission mode emits light, the injection current Ion for the channel in the non-light emission mode is set to 0. An injection current may be given although it is minute. Even in such a case, the relationship of Ion <Ioff is determined.
In the following description, in the description related to temperature control, a channel in the light emission mode is referred to as a main channel and a channel in the non-light emission mode is referred to as a sub-channel or a temperature control unit in order to avoid complexity.

FIG. 18 is a diagram for explaining an example in which means for storing an operation history is provided.
In the figure, reference numeral 30 denotes a main channel, 31 denotes a sub-channel, and 32 denotes a control circuit.
The signal history of the main channel 30 is stored, and when the estimated temperature rise of the main channel is expected to be equal to or higher than a predetermined temperature based on the history, a drive signal for the sub channel 31 is generated at that timing to generate the sub channel 31. Is provided with a control circuit 32 capable of driving.

FIG. 19 is a diagram for explaining another embodiment.
In the figure, reference numeral 33 denotes a temperature sensor, 34 denotes a determination circuit, and 35 denotes a sub-channel drive circuit.
It is also possible to implement a method for determining the timing of switching the operations via the main / sub drive circuit 35 by the judgment circuit 34 that judges when the temperature measured by the temperature sensor 33 exceeds a predetermined value. In the figure, the main channel drive circuit is not shown.

FIG. 20 is a schematic diagram showing the relationship between the light emission time of the main channel and the temperature change.
In the same figure, the code | symbol Tt is a diagram which shows a temperature change.
The temperature change Tt in the main channel increases as the light emission time in the main channel increases, and decreases as the non-light emission time in the main channel increases. Therefore, temperature control according to the light emission and non-light emission signal patterns in the main channel is performed. By using this, the accuracy of temperature control for the main channel can be improved.
When the non-light emission time in the main channel is long (light emission time is short), the integrated value of the current injected into the sub-channel is increased, and conversely, when the light emission time in the main channel is long, the integrated value of the current injected into the sub-channel is decreased. As a result, temperature fluctuations in the main channel are suppressed.
Since the integrated value of the injection current is a product of the injection amount per unit time and the injection time, the temperature can be controlled using at least one of these two control parameters.

FIG. 21 is a diagram schematically showing temperature fluctuation characteristics of the main channel accompanying current injection into both the main and sub channels.
In the figure, reference numerals 36 and 39 are main channel injection current regions, 37 and 45 are main channel temperature rise regions, 38, 41, 44 and 46 are sub channel injection current regions, and 40, 42 and 43 are main channels. , I ₁ is an injection current into the main channel, I ₂ is an injection current into the sub-channel, and Top is a desired temperature region for the main channel.
When the main channel is in a light emitting state, the temperature of the main channel rises as indicated by reference numeral 37 as heat is generated. Therefore, it is preferable to operate the sub-channel so as to cool it. More specifically, so as not to inject the current I ₂ as shown in the injection current region 38. As a result, the sub-channel does not generate heat and can absorb and dissipate the heat of the main channel, so that the temperature rise of the main channel is suppressed.

Next, as shown in the main channel injection current region 39, when the main channel is in a non-light emitting state (I ₁ = 0), the remaining heat is dissipated as shown in the main channel temperature drop region 40. The temperature of the main channel decreases. In this heat release process, as shown in the injection current region 41 of the secondary channel, by preventing injected current I ₂ to the secondary channel, it is possible to increase the temperature lowering effect of the main channel. As a result, the temperature drop region 42 of the main channel falls within the desired temperature region Top.

Next, when the non-light emission time is further extended and the main channel temperature is lower than the desired temperature Top as shown in the temperature drop region 43 of the main channel, the non-light emission time is shown in the injection current region 44 of the subchannel. Thus, the current I ₂ can be injected into the sub-channel to raise the temperature of the main channel. When the temperature rises and reaches a desired temperature region Top as shown in the temperature increase region 45 of the main channel, the current injection amount is reduced or not injected as shown in the injection current region 46 of the subchannel. To.
As described above, in the non-light emitting state, these two control patterns can be appropriately selected according to the non-light emitting time. Therefore, the amount of current injected into the subchannel when the main channel emits light is preferably smaller than the amount of current injected into the subchannel when the main channel does not emit light.

  When there are a plurality of main channels, it is preferable to perform the injection current control in consideration of the fact that the temperature fluctuation characteristics are not uniform. Since it is rare that the signal pattern of any channel is always the same, the temperature fluctuation characteristics also differ depending on the channel, so the amount of injected current is controlled independently for each main channel, and the signal pattern of each channel is By performing current injection control, temperature control suitable for each channel is performed, and temperature variation of the entire channel can be reduced. Even in this case, since the integrated value of the injection current is the product of the injection amount per unit time and the injection time, it is possible to correct these as control parameters.

FIG. 22 is a schematic diagram for explaining the relationship between the injection current level and the time width.
In the figure, reference numerals 47 and 48 denote waveforms of current injected into the subchannel, i denotes a current level, and t denotes a time width.
The current level is i for waveform 47 and 2i for waveform 48, and the injection time is t for waveform 47 and 1 / 2t for waveform 48. If the injection current is not for the purpose of light emission, 2i is smaller than the threshold current required for light emission.
The current level of the waveform 48 is twice that of the waveform 47, but the injection time width is ½. Therefore, when viewed as an integrated value, the waveform 47 and the waveform 48 are equivalent.

FIG. 23 is a diagram for explaining the difference in cooling effect depending on the arrangement conditions of the light emitting units.
In the figure, reference numeral 49 denotes a central light emitting portion, and 50 denotes a peripheral light emitting portion.
When the main channels are arranged in a one-dimensional or two-dimensional array, the heat radiation effect in the central light emitting section 49 of the array is relatively lower than that in the array peripheral light emitting section 50 as shown in FIG. It is desirable to perform control so that the cooling effect is relatively higher than that of the peripheral light emitting unit 50 by lowering the injected current. In the figure, the secondary channel is omitted.

FIG. 24 is a diagram for explaining a configuration example for increasing the heat dissipation effect.
In the figure, reference numeral 51 denotes a secondary channel.
Increasing the heat dissipation effect is also effective, and as shown in the figure, it is preferable to arrange a large number of subchannels 51 in the channel arrangement surface so that the action of the subchannel as a heat dissipation member is strengthened.
In addition, one or a plurality of subchannels can be used for temperature control of the main channel. In particular, in the case of a plurality of subchannels, the control can be performed more strongly as the number of subchannel channels increases. When it is desired to strongly suppress the temperature rise of the main channel, heat can be absorbed and heat radiation can be accelerated by using more subchannels. Alternatively, when it is desired to strongly suppress the temperature drop of the main channel, the amount of heat transfer can be increased using more subchannels.

It is also possible to prepare a number of sub-channels in advance and adjust the number of channels driven for temperature control as required. As shown in the figure, the peripheral light emitting section 50 of the array arrangement is also configured so that the number of subchannels of the central light emitting section 49 is relatively large, so that the operation of the central main channel in which heat is difficult to escape is stabilized. Can do.
When you need to switch one of multiple sub-channels to a light emission channel,

FIG. 25 is a diagram illustrating an arrangement example in consideration of a difference in heat radiation effect depending on a place.
The interval between the light emitting channels is wider at the center than at the periphery in the channel arrangement plane.
As described above, when the main channels are arranged in a one-dimensional or two-dimensional array, the heat radiation effect in the central portion is relatively low. Therefore, as shown in the figure, the main channel 49 and the main channels 50 ₁ , 50 It may be used in combination with a configuration in which the interval 50d of ₂ is relatively wide in the central portion. For example, in the figure, 50d1 is longer than 50d2. In addition, a large number of hatched sub-channels 51 can be arranged in the gap between the main channels widened by arranging the main channels in this way, so that the heat dissipation can be improved. Thereby, the effect which suppresses the temperature rise of a center part can be heightened.

For example, the volume of a VCSEL subchannel having a cylindrical pillar shape can be defined by the height and diameter of the pillar, but the diameter can be freely changed according to the opening shape of a mask used in a deposition process represented by MOCVD. . By changing the diameter, the volume changes and the heat capacity can also change.
That is, the total volume of the temperature control unit is configured to be larger in the central part than in the peripheral part in the channel arrangement plane. Or it comprises so that the exposed surface area of a temperature control part may become large.
For example, by reducing the diameter of the subchannels near the center of the array array and reducing the heat capacity per unit, the heat dissipation response becomes faster. By arranging a large number of these, the total amount of heat dissipation can be increased. it can. Thereby, the temperature rise of the main channel in the vicinity of the center can be suppressed with good response. Of course, the height may be changed, and when the shape is not cylindrical, it can be changed according to the opening shape of the mask.

FIG. 26 is a diagram showing that the hysteresis loop characteristic indicating polarization bistability has temperature dependence. FIGS. 4A to 4E are curves showing hysteresis loops corresponding to 195.2 ° K to 184.5 ° K, respectively.
In the drawing, the symbol TM indicates a TM mode oscillation graph, and the TE indicates a TE mode oscillation graph.
In each figure, the horizontal axis represents current (CURRENT): unit [mA], and the vertical axis represents light output (POWER): unit [mW].
A polarization bistable VCSEL exhibits excellent ultrafast polarization switching characteristics and is known to be capable of switching on the order of picoseconds, and proposed an excellent function such as an optical 2R function for demodulating a degraded signal, Application to optical communication is expected. In the non-patent document 1 of KAWAGUCHI et al., As shown in the figure, the hysteresis loop characteristic showing polarization bistability has temperature dependence, and the temperature range showing the hysteresis loop characteristic is limited. It is simultaneously shown that the hysteresis loop characteristic disappears when a predetermined temperature range is exceeded.
In the above, the TM mode refers to a waveguide mode having no magnetic field component in the wave propagation direction, and the TE mode refers to a waveguide mode having no electric field component in the wave propagation direction.
This hysteresis loop is a characteristic directly related to the bistability that appears in the relationship between the injection current amount and the light emission intensity, and the optical bistability characteristic cannot be obtained unless the temperature is within the temperature range where the hysteresis loop characteristic can be obtained. Therefore, temperature control is extremely important. At present, temperature control using Peltier elements is performed, and the cost required for temperature control is not low, but it is expected that reducing the temperature correction cost will be important in the future as well as in consumer metropolitan systems. . Even in such a polarization bistable VCSEL array, as described above, an optical signal can be generated by a temperature control mechanism, a pillar structure, or one or a plurality of subchannels and a current injection drive control method for them. The temperature of the main channel to be used can be controlled, and the cost required for temperature control is reduced.

  Also, in the polarization bistable VCSEL as described above, the TM polarization state and the TE polarization state rotated 90 degrees are often used by switching, and these two polarization modes are stable. A pumped laser structure is desirable. A strained superlattice structure that satisfies this is strained in a specific direction, but polarization bistability may also be disrupted due to changes in strain characteristics due to expansion and contraction of the constituent materials due to thermal changes. It is suggested. By reducing the temperature fluctuation range, the expansion and contraction of the material and the accompanying change in strain characteristics can be suppressed. In particular, a high effect can be obtained in maintaining polarization bistability by selecting a position where a temperature change of a directional component that exhibits polarization bistability is less likely to occur and providing a subchannel to suppress temperature fluctuation.

FIG. 27 is a diagram for explaining another embodiment of the present invention.
This figure schematically shows a VCSEL that excites an elliptically polarized wave 53 having a principal axis in the 45 ° right oblique direction and an elliptically polarized wave 54 having the principal axis in the 45 ° oblique left direction. Since the sub-channels are arranged in the 45 ° oblique direction to the left, the temperature controllability in these directions is high, so that the stability of characteristics can be enhanced. Based on this example, in the case where there are a plurality of main channels, in the same manner, the right diagonal 45 ° direction and the left are set for each main channel so that the temperature controllability becomes high in these directions. Subchannels can be arranged and arranged in an oblique 45 ° direction.

  Also in the optical communication field, high-speed and large-capacity communication is expected by using multi-channel light sources. However, according to the present invention, optimum temperature correction can be performed for each of the multi-channels. become.

FIG. 28 is an application diagram to a phase delay writing type apparatus in recent years. The figure (a) is a top view, The figure (b) is a side view.
In the drawing, reference numeral 55 denotes a semiconductor laser light source, 56 denotes a collimator lens, 57 denotes an optical path separating means, 58 denotes a cylindrical lens, 59 denotes an optical deflector, 60 denotes a scanning lens, 61 denotes a folding mirror, and 62 denotes a photoreceptor surface. In FIG. 6B, for example, a polarization beam splitter is used as the optical path separating means 57a. The optical path separating means 57b is an element for deflecting the optical path separated by 57a. In the figure, the optical path separating means 57b is deflected by 90 degrees, and the two separated optical paths are configured in parallel. The vertical direction in the figure coincides with the sub-scanning direction in writing. The optical deflector 59 is composed of two stages of polygon mirrors, and the phase of deflection scanning is shifted by 90 degrees between the upper stage and the lower stage, so that writing scanning can be alternately performed at high speed using two optical paths.
By using the VCSEL array 55 as a light source for this optical apparatus, a plurality of rows of main scanning writing can be performed on the photoreceptor surface 62. Alternatively, when a polarization bistable VCSEL is used, writing scanning using two optical paths can be performed at high speed by using the optical path separation element 57a as a polarization beam splitter.

  Furthermore, if a polarization bistable VCSEL array is used as the light source 55, writing in a plurality of columns can be performed in one main scan, so that writing can be performed at higher speed. In particular, when writing a plurality of main scan rows at the same time, it is important to improve the image quality that the beam spot quality in each scan row is uniform. In order to prevent variation in the light emission characteristics of each channel of the VCSEL array, temperature control using a sub-channel can be performed for each channel. As a result, variations in the light emission characteristics of each channel can be improved. By making the beam quality, in particular, the emission beam intensity and the beam spot diameter uniform, the dot size formed on the photosensitive member is made uniform, and the effect of improving the image quality is high. In addition, since the refraction and reflection characteristics due to the optical elements that occur during the propagation of the optical path have polarization dependence, these characteristics fluctuations are suppressed by improving the variation in the polarization characteristics of the emitted light beam, Since the characteristics (light quantity, profile, etc.) of the spot that reaches the surface of the photosensitive member are made uniform, variations in the latent image spot recorded on the surface of the photosensitive member are similarly suppressed. These effects can improve the image quality.

  Alternatively, a plurality of main scan columns can be simultaneously written by the VCSEL array without using the optical path separating means and the two-stage polarizer as shown in FIG. On the other hand, it goes without saying that the effect of improving the image quality can also be obtained by performing the temperature control described so far.

FIG. 29 is a diagram showing an example in which the present invention is used in a tandem type image forming apparatus.
In the figure, reference numeral 63 denotes an optical scanning device, 64 denotes a transfer belt, 65 denotes a photosensitive member, 66 denotes a charger, 67 denotes a developing unit, 68 denotes transfer means, 69 denotes cleaning means, and suffixes y, c, m, and k denote yellow. , Cyan, magenta, and black development colors are shown.
An image forming apparatus can be configured using the above optical scanning writing optical system. Thereby, high image quality can be realized at high speed and high density. For example, a tandem color image forming apparatus can be realized using an optical scanning writing optical system.

  The color image forming apparatus has four photoconductors 65y, 65m, 65c, and 65k juxtaposed along the moving direction of the transfer belt 64. Around the photosensitive member 65y for yellow image formation, a charger 66y, a developing device 67y, a transfer unit 68y, and a cleaning unit 69y are arranged in this order in the rotation direction indicated by the arrow. The other colors have the same configuration, and the charger 66 is a charging member that constitutes a charging device for uniformly charging the surface of the photoreceptor. An optical latent image is formed on the photosensitive member 65 by irradiating the photosensitive member surface with a beam between the charging unit 66 and the developing unit 67 by the optical scanning device 63. Then, based on the electrostatic latent image, a toner image is formed on the photoreceptor surface by the developing device 67. The transfer unit 68 sequentially transfers the transfer toner images of the respective colors onto a recording medium (transfer sheet: not shown) conveyed by the transfer belt 64, and finally the superimposed image is fixed on the transfer sheet by the fixing unit 70. .

  In the case of optical scanning writing, in order to give gradation to an image, a modulation method such as modulating the intensity of a light spot or modulating the pulse width with a constant intensity of the light spot is adopted. Also in optical communication, there are modulation schemes that combine pulse width modulation, pulse intensity modulation, pulse polarization characteristic modulation, etc., for signal multiplexing.

  In addition to the embodiments shown so far, even when the “intensity” of the pulse is modulated, the integrated value of the pulse signal intensity and the pulse width is related to the temperature fluctuation. By performing the current injection control, appropriate temperature control for each pulse can be performed by the operation and action described above.

  Further, in the embodiments described so far, the description has been made mainly on the drive control of giving the temperature control one by one corresponding to each of the pulse signals. However, the present invention is not limited to this. It is also possible to control the temperature for the time product of the emission intensity obtained by sampling the pulse signal. For a pulse signal sequence generated within a predetermined time, two product sums, which are a product of light emission intensity and a non-light emission time multiplied by a predetermined negative coefficient value k, are regarded as index values. If the control is performed so as to balance the injection time product of the injection current value into the subchannel, the number of on / off times of the subchannel is reduced, and the required switching operation speed is reduced.

  In the case of this driving method, the temperature control as a result of sampling in the time zone A1 is performed in the next sampling time zone A2, so that the action of the temperature control affects the light emission in the next sampling time zone A2. Therefore, in the time zone A3 in which the next temperature control is performed, it is preferable to give a correction value in which the influence of both the light emission signal and the temperature control signal in the time zone A2 is added. As described above, it is preferable to consider that the operation effect of the temperature control affects the light emission in the next sampling time zone, and this is the same in the subsequent sampling time zones.

It is a figure for demonstrating embodiment of this invention. It is a figure which shows the structure which improved heat dissipation. It is a figure for demonstrating other embodiment. It is a schematic diagram which shows the temperature change of the light emission channel by the electric current injection to a temperature control mechanism. It is a figure for demonstrating other embodiment. It is a figure for demonstrating other embodiment. It is a figure for demonstrating other embodiment. It is a figure for demonstrating the pillar structure which improved heat absorption efficiency. It is a schematic diagram which shows an electric current injection direction. It is a figure for demonstrating other embodiment. It is a figure for demonstrating other embodiment. It is a side view of a VCSEL array. It is a figure which shows the example of arrangement | positioning of the subchannel with respect to the main channel. It is a figure which shows the example of arrangement | positioning of the subchannel with respect to the main channel. It is a figure which shows the example of arrangement | positioning of the subchannel with respect to the main channel. It is a figure which shows the example of arrangement | positioning of the subchannel with respect to the main channel. It is a figure for demonstrating the example which switches the input signal of a main channel and a subchannel. It is a figure for demonstrating the example which provides the means to memorize | store an operation history. It is a figure for demonstrating other embodiment. It is a schematic diagram which shows the relationship between the light emission time of a main channel, and a temperature change. It is a figure which shows typically the temperature fluctuation characteristic of the main channel accompanying the current injection into the channel of both main and sub. It is a figure for demonstrating the relationship between an injection electric current level and a time width. It is a figure for demonstrating the difference in the cooling effect by the conditions of arrangement | positioning of a light emission part. It is a figure for demonstrating the structural example which makes the heat dissipation effect high. It is a figure which shows the example of arrangement | positioning which considered the difference of the thermal radiation effect by a place. It is a figure which shows that the hysteresis loop characteristic which shows polarization bistability has temperature dependence. It is a figure for demonstrating other embodiment of this invention. It is an application diagram to a phase delay writing type apparatus in recent years. It is a figure which shows the example which uses this invention for a tandem type image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emission channel 2 Temperature adjustment part of a thick pillar 3 Temperature adjustment part of a thin pillar 4 Side surface of a light emission channel 5 Inner side surface of a temperature adjustment part 9, 11, 13 Light emission channel 10, 12, 14 Temperature adjustment part 32 Control circuit 33 Temperature sensor 34 Judgment circuit 35 Sub channel drive circuit

Claims (22)

  A surface-emitting type semiconductor laser device having a plurality of light-emitting channels used for generating an optical signal, comprising one or more temperature adjusting units for adjusting the temperature of one light-emitting channel or a plurality of light-emitting channels. The surface emitting semiconductor laser device is characterized in that when the temperature of the temperature adjusting unit is lower than the temperature of the light emitting channel, the temperature adjusting unit absorbs heat of the light emitting channel.   2. The surface-emitting type semiconductor laser device according to claim 1, wherein the temperature adjusting unit has a configuration capable of injecting current, and by injecting current into the temperature adjusting unit, the temperature of the temperature adjusting unit is increased, A surface-emitting type semiconductor laser device characterized in that the temperature of the light-emitting channel can also be increased by heat of a temperature adjusting unit.   3. The surface-emitting type semiconductor laser device according to claim 1, wherein the temperature adjusting unit starts from a channel (hereinafter referred to as a sub channel for convenience) having a function equivalent to that of the light emitting channel (hereinafter referred to as a main channel). A surface-emitting type semiconductor laser device.   4. The surface emitting semiconductor laser device according to claim 1, wherein a plurality of temperature control units are associated with positions where temperature control is possible with respect to one light emitting channel. Surface emitting semiconductor laser device.   5. The surface-emitting type semiconductor laser device according to claim 1, wherein the number of temperature control units for one light-emitting channel is associated with a larger number in a central part than in a peripheral part in a channel arrangement plane. A surface-emitting type semiconductor laser device characterized by that.   6. The surface emitting semiconductor laser device according to claim 1, wherein a distance between the light emitting channels is wider at a center portion than at a peripheral portion in the channel arrangement surface. Surface emitting semiconductor laser device.   7. The surface-emitting type semiconductor laser device according to claim 1, wherein the central portion of the surface emitting semiconductor laser device has a larger total volume than the peripheral portion in the channel array plane. A surface-emitting type semiconductor laser device comprising:   8. The surface-emitting type semiconductor laser device according to claim 1, wherein the exposed surface area of the temperature adjusting portion is larger in the central portion than in the peripheral portion in the channel arrangement surface. A surface-emitting type semiconductor laser device comprising:   9. The surface-emitting type semiconductor laser device according to claim 1, wherein the temperature adjusting unit has a function as a heat radiating fin.   10. The surface-emitting type semiconductor laser device according to claim 1, wherein two or more temperature adjusting units that control the temperature of the light emitting channel are associated with one or more light emitting channels. A surface-emitting type semiconductor laser device characterized by that.   11. The surface-emitting type semiconductor laser device according to claim 1, wherein the surface-emitting type semiconductor laser device is a polarization bistable type.   11. A driving method for driving a surface emitting semiconductor laser device according to claim 3, wherein a light emission mode is switched from the main channel to the sub channel at a predetermined timing, A surface emitting semiconductor characterized in that a main channel is in a non-light-emitting mode, a light-emitting mode is switched from the sub-channel to the main channel at another predetermined timing, and the sub-channel is in a non-light-emitting mode Driving method of laser apparatus.   13. The driving method for driving a surface emitting semiconductor laser device according to claim 12, wherein the channel in the non-emitting mode is caused to function as a temperature control unit.   14. The driving method for driving the surface emitting semiconductor laser device according to claim 13, wherein the amount of current injected per unit time into the channel of the temperature control unit is reduced when the light emission time of the channel in the light emission mode is long. A driving method of a surface emitting semiconductor laser device, wherein the driving is performed so as to increase when the non-light emitting time is long.   15. The method of driving a surface-emitting type semiconductor laser device according to claim 13, wherein the channel of the temperature adjusting unit is controlled in the amount of injected current independently for each channel in the corresponding emission mode. Driving method of surface emitting semiconductor laser device.   16. The method of driving a surface emitting semiconductor laser device according to claim 13, wherein a time for injecting a current into the channel of the temperature adjusting unit is short when a light emission time of the channel in the light emission mode is long. And a driving method of the surface emitting semiconductor laser device, wherein the driving is performed so that the non-light emitting time is long when the light emitting time is long.   17. The surface emitting semiconductor laser device driving method according to claim 16, wherein the channel of the temperature adjusting unit is controlled in current injection time independently for each channel in a corresponding emission mode. Type semiconductor laser device driving method.   16. The method for driving a surface-emitting type semiconductor laser device according to claim 13, wherein a current injected into the channel of the temperature control unit when the channel in the emission mode emits light or does not emit light. A driving method of a surface emitting semiconductor laser device, wherein current is injected so that Ion <Ioff when Ion and Ioff, respectively.   19. The surface emitting semiconductor laser device driving method according to claim 13, wherein when there are a plurality of channels of the temperature adjusting unit, the number of channels used for temperature control is set to a channel in the emission mode. A method of driving a surface-emitting type semiconductor laser device, wherein the surface-emitting type semiconductor laser device is selectively driven so as to increase when a temperature difference between channels used for temperature control is large.   20. The method of driving a surface emitting semiconductor laser device according to claim 12, wherein the surface emitting semiconductor laser is a polarization bistable type. Method.   12. An optical scanning device having a light source, an optical scanning means, and an imaging optical system, wherein the light source is the surface-emitting type semiconductor laser device according to any one of claims 1 to 11. Scanning optical device.   An image forming apparatus including at least an optical scanning optical device, a plurality of photosensitive members, a developing device, and a transfer device, wherein the optical scanning optical device is the optical scanning optical device according to claim 21. Image forming apparatus.

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