HK1028108B - Timepiece - Google Patents

Description

Clock device

Technical Field

The present invention relates to a timepiece device such as a wristwatch and a watch clock that displays time information and calendar information on a liquid crystal panel, and more particularly to a timepiece device having a backlight for transmission-type display.

Technical Field

A timepiece device that digitally displays time information such as minutes, seconds, or calendar information such as the year, month, day, and week is widely used as a digital timepiece. These digital displays are almost all realized by liquid crystal display panels.

In this liquid crystal display panel, although a Super Twisted Nematic (STN) liquid crystal is used for some panels, a Twisted Nematic (TN) liquid crystal is mostly used.

For practical use in display, a polarizing plate is combined with an STN liquid crystal or a TN liquid crystal for contrast generation, and a polarizing plate used in a liquid crystal display panel is an absorption polarizing plate that absorbs linearly polarized light having a plane of vibration orthogonal to a transmission easy axis.

Although such liquid crystal display panels are used in many common digital watches, it is known that if a Light Emitting Diode (LED) is combined as a backlight, the liquid crystal display panels are interesting in design, and thus the liquid crystal display panels are commercialized in many cases.

The reason why the liquid crystal display panel and the LED as the backlight are combined is as follows: in order to perform digital display using LEDs, LEDs are expensive, liquid crystal display panels are inexpensive compared to the number of segments of digital display, and finer patterns can be displayed using liquid crystal display panels.

When a liquid crystal display panel is used and LEDs are used as a backlight, 2 to 3 LEDs may be used, although the area of the display portion is concerned. Further, it is advantageous even if the power consumption of the liquid crystal display panel is much lower in terms of power consumption.

Here, a conventional timepiece device having a liquid crystal display panel and a backlight with an LED will be described in more detail with reference to the drawings.

Fig. 7 is a schematic perspective view showing an example of the configuration of a numeral display portion for displaying the time information or the calendar information.

A TN liquid crystal layer 105 having a twist angle of 90 degrees is sealed with a sealant (not shown) and sandwiched between a 1 st glass substrate 101 and a 2 nd glass substrate 104, which have transparent electrodes (not shown) formed on their inner surfaces facing each other, to form a liquid crystal display panel 100.

A 1 st absorbing polarizing plate 102 is disposed on the outer side of the 1 st glass substrate 101 on the viewing side, and a 2 nd absorbing polarizing plate 103 is disposed on the outer side of the 2 nd glass substrate 104.

The 1 st and 2 nd absorption polarizers 102 and 103 and the liquid crystal display panel 100 are arranged such that the easy axis of transmission 102a of the 1 st absorption polarizer 102 is parallel to the long axis direction of the liquid crystal molecules on the 1 st glass substrate 101 side of the TN liquid crystal layer 105, and the easy axis of transmission 103a of the 2 nd absorption polarizer 103 is perpendicular to the long axis direction of the liquid crystal molecules on the 2 nd glass substrate 104 side of the TN liquid crystal layer 105.

On the side opposite to the viewing side of the 2 nd absorbing polarizer 103, a diffusion layer 106 and a backlight 108 composed of 2 red LEDs 107 are disposed. The diffusion layer 106 is formed of a thick plate or thick paper made of polycarbonate or acrylic resin, or an adhesive containing particles for diffusing the particles, and the surface may be embossed for improving the diffusion property.

In this way, when the liquid crystal display panel 100 and the 2 absorption polarizing plates 102 and 103 are arranged, a display mode in which characters indicating time and the like are displayed through a black background called normal display black is achieved.

Fig. 8 shows a display state when the backlight is operated. When the LED107 of the backlight emits light in the state of fig. 7, out of the light emitted from the red LED107, a linearly polarized light component having a vibration plane parallel to the easy transmission axis of the 2 nd absorption polarizing plate 103 transmits. Since the display characters in fig. 8 are portions where a voltage is applied between electrodes, not shown, of the liquid crystal display panel 100, the linearly polarized light passes through the TN liquid crystal layer 105 without being distorted, and becomes a red light emission display color as linearly polarized light having a vibration plane parallel to the transmission easy axis of the 1 st absorption type polarizing plate 103 passes through the polarizing plate to the viewing side.

On the other hand, since the background portion 52 in fig. 8 is a portion where no voltage is applied between the electrodes of the liquid crystal display panel 100, the linearly polarized light transmitted through the absorption polarizing plate 103 is distorted by 90 degrees in its vibration plane when passing through the TN liquid crystal layer 105, and is in a direction perpendicular to the easy axis of transmission of the 1 st absorption polarizing plate 103, and is absorbed by the absorption polarizing plate 102, and becomes black.

Thus, in the configuration of fig. 7, when the red LED107 of the backlight 108 emits light, only the portion where the characters 51 are displayed transmits the light emitted from the red LED107, and the characters are displayed in red on a black background.

Next, a case when the backlight is not emitting light will be described. Fig. 9 shows a display state when the backlight is not lit.

If the red LED107 of the backlight 108 emits no light in the state of fig. 7, the linearly polarized light having a vibration plane parallel to the easy axis of transmission thereof among the light incident from the viewing side is transmitted through the absorption polarizing plate 103 of fig. 1. Since the display characters 61 in fig. 9 are portions where a voltage is applied between the electrodes of the liquid crystal display panel 100, the linearly polarized light thereof is transmitted through the TN liquid crystal layer without being distorted, and is changed into linearly polarized light having a plane of oscillation parallel to the transmission easy axis of the 2 nd absorption polarizing plate 103, and reaches the diffusion layer 106 of the backlight 108 through the polarizing plate. In the diffusion layer 106, the incident linearly polarized light is diffused only in the direction of the red LED107, and since there is no reflection layer exhibiting strong reflection characteristics under the diffusion layer 106, the display color becomes black.

Since no voltage is applied between the electrodes of the liquid crystal display panel 100, the background portion 62 in fig. 9 is a portion where the linearly polarized light transmitted through the 1 st absorbing polarizer 102 is distorted by 90 degrees in its vibration plane when passing through the TN liquid crystal layer 105, and is in a direction perpendicular to the easy axis of transmission of the 1 st absorbing polarizer 102, and is absorbed by the absorbing polarizer 102, and becomes black.

Therefore, in the configuration shown in fig. 7, in the non-light-emission state of the backlight, the portion where the characters 61 are displayed becomes black, and the background portion 62 also becomes black.

As described above, in the conventional digital display timepiece device using a liquid crystal display panel having a light source such as an LED as a backlight, when the backlight is not emitting light, as shown in fig. 9, in the reflective display by external light, the display becomes black on a black background, and thus there is a problem that contrast cannot be obtained. That is, it is impossible to view the display of the time, date, etc. as long as the backlight does not emit light.

This is because the polarizing plate used in the conventional liquid crystal display panel is an absorption-type polarizing plate, and when combined with a TN liquid crystal layer, it switches between black which is transmitted and absorbed by the polarizing plate. That is, in fig. 9, the background portion 62 is black due to absorption by the polarizing plate, and the character display 61 is black due to the diffusion layer 106, so that contrast cannot be generated, and recognition of characters becomes difficult. When recognition of characters becomes difficult in this way, it is necessary to cause a backlight to emit light every time confirmation is desired in order to confirm a time display or the like, and this is not only inconvenient to use but also requires a large amount of power, and therefore, this has become a major problem as a timepiece device.

Disclosure of the invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide a timepiece device which can display with a high contrast so that time information, calendar information, and the like can be recognized by a liquid crystal display panel even when a backlight is not emitting light.

The timepiece device of the present invention is a timepiece device in which a liquid crystal layer is sealed in a gap between a 1 st substrate and a 2 nd substrate having electrodes formed on opposite surfaces thereof, and at least one of time information and calendar information is displayed, wherein a 1 st polarizing plate is disposed outside the 1 st substrate on a viewing side of the liquid crystal display panel, a 2 nd polarizing plate is disposed outside the 2 nd substrate, and a backlight is provided on a side opposite to the viewing side of the 2 nd polarizing plate.

The 1 st polarizing plate is an absorption polarizing plate that absorbs linearly polarized light having a plane of vibration perpendicular to the easy axis of transmission, and the 2 nd polarizing plate is a reflection polarizing plate that reflects linearly polarized light having a plane of vibration perpendicular to the easy axis of transmission.

In the case where the liquid crystal layer sealed in the gap between the 1 st substrate and the 2 nd substrate of the liquid crystal display panel is a twisted nematic liquid crystal having a twist angle of 90 degrees or less, the absorption polarizing plate may be disposed such that a transmission easy axis of the absorption polarizing plate is substantially parallel to or perpendicular to a long axis direction of liquid crystal molecules on a viewing side of the twisted nematic liquid crystal with respect to the liquid crystal display panel, and the reflection polarizing plate may be disposed such that a transmission easy axis of the reflection polarizing plate is substantially parallel to or perpendicular to a long axis direction of liquid crystal molecules on a backlight side of the twisted nematic liquid crystal with respect to the liquid crystal display panel.

When the liquid crystal layer sealed in the gap between the 1 st substrate and the 2 nd substrate of the liquid crystal display panel is super twisted nematic liquid crystal having a twist angle of 180 degrees to 270 degrees, a retardation plate may be provided between the 1 st substrate and the absorption polarizing plate of the liquid crystal display panel.

In these timepiece devices, a diffuser plate may be provided on the liquid crystal display panel side of the reflective polarizing plate. As the absorption polarizing plate, a color polarizing plate using a 2-color dye may be used.

The backlight may be configured with a light source such as a light emitting diode or photoluminescence light, and a diffusion layer for diffusing light emitted from the light source.

The diffusion layer can be formed by a coating film in which silica particles or polyacrylic resin particles are diffused into a transparent adhesive. Alternatively, a color filter may be used as the diffusion plate.

With the timepiece device according to the present invention, by providing the reflective polarizing plate on the backlight side of the liquid crystal display panel, it is possible to perform a reflective display by external light with a good contrast and also to perform a display by transmitted illumination of the backlight with sufficient brightness.

Brief description of the drawings

Fig. 1 is a schematic perspective view showing embodiment 1 of the timepiece device of the invention. Fig. 2 and 3 are schematic oblique views showing display states when the backlight is lit and when the backlight is not lit.

Fig. 4 is a schematic perspective view showing embodiment 2 of the timepiece device of the invention. Fig. 5 and 6 are schematic oblique views showing display states when the backlight is lit and when the backlight is not lit.

Fig. 7 is a schematic perspective view showing a configuration example of a conventional timepiece device. Fig. 8 and 9 are schematic oblique views showing display states when the backlight is lit and when the backlight is not lit.

PREFERRED EMBODIMENTS

Preferred embodiments of the timepiece device according to the invention are explained below with reference to the drawings.

Example 1

First, embodiment 1 of the timepiece device according to the invention will be described with reference to fig. 1 to 3.

Fig. 1 is a schematic perspective view showing embodiment 1 of the timepiece device of the invention. Fig. 2 and 3 show a display state when the backlight emits light and a display state when the backlight does not emit light, respectively.

In fig. 1, a 1 st substrate 1 and a 2 nd substrate 4 each made of glass having a thickness of 0.5mm are bonded to each other with a sealant not shown provided around them, and a TN liquid crystal layer 5 having a twist angle of 90 degrees is sealed in a gap therebetween to constitute a liquid crystal display panel. Display electrodes and counter electrodes (not shown) made of ITO, which is a transparent conductive film itself, are formed on the facing inner surfaces of the 2 nd substrate 1 and the 2 nd electrode plate 4, respectively.

An absorbing polarizing plate 2 is disposed as a 1 st polarizing plate on the outer side of a 1 st substrate 1 on the viewing side of the liquid crystal display panel 10, and a reflecting polarizing plate 3 is disposed as a 2 nd polarizing plate on the outer side of a 2 nd substrate 4.

The absorption polarizer 2 is a sheet-like member that absorbs linearly polarized light having a vibration plane perpendicular to the easy axis of transmission, and is a member having a relatively high transmittance of 46% even in a general polarizer, for example, a stretched PVA (polyvinyl alcohol) film dyed with iodine is sandwiched between TAC (triacetyl cellulose) films.

The absorption polarizing plate 2 is disposed so that the long axis direction of the liquid crystal molecules on the viewing side (the 1 st substrate 1 side) of the TN liquid crystal layer 5 of the liquid crystal display panel 10 is parallel to the easy transmission axis 2a of the absorption polarizing plate 2.

The reflective polarizing plate 3 is a sheet-like member that reflects linearly polarized light having a plane of oscillation perpendicular to the easy axis of transmission, and is a member in which a multilayer film is formed on a base film, and for example, D-BEF (trade name) sold by sumitomo 3M co.

By using this reflective polarizing plate, light that has been absorbed by the absorbing polarizing plate can be reflected.

The emission polarizing plate 3 is disposed so that the long axis direction of the liquid crystal molecules in the TN liquid crystal layer 5 (the 2 nd substrate 4) of the liquid crystal display panel 10 on the side opposite to the viewing side is perpendicular to the transmission easy axis 3a of the reflection polarizing plate 3 (parallel to the reflection axis 3 b).

On the side opposite to the viewing side of the reflective polarizing plate 3, a backlight 8 composed of 2 red LEDs and a diffusion layer 6 for diffusing light emitted from the LEDs is disposed.

The diffusion layer 6 is a member exhibiting light diffusion properties, such as a thick plate or thick paper made of polycarbonate or acrylic resin, or a coating film of a transparent adhesive in which silica particles or acrylic resin particles having diffusion properties are diffused. In order to further improve the diffusibility, embossing or the like may be performed. In this example, a thick plate of acrylic resin having a thickness of 3mm was used.

In this embodiment, if the absorption polarizing plate 2 and the reflection polarizing plate 3 are arranged in the direction as shown in fig. 1, a mode is adopted in which characters such as display time information are transmitted in a background portion which is called normal reflection display and reflects. This display will be described in more detail.

Fig. 2 shows a display state when the backlight emits light.

When the red LED7 of the backlight emits light, a linearly polarized light component having a vibration plane parallel to the transmission easy axis 3a of the reflective polarizing plate 3 is incident on the liquid crystal display panel 10 through the reflective polarizing plate 3, within the light emitted from the red LED 7.

Since the display characters 11 in fig. 2 are portions where a voltage is applied between electrodes, not shown, of the liquid crystal display panel 10 in fig. 1, linearly polarized light having passed through the reflective polarizing plate 3 passes through the liquid crystal layer 5 without being distorted, and linearly polarized light having a vibration plane parallel to the transmission easy axis 2a of the absorptive polarizing plate 2 passes through the absorptive polarizing plate 2 as it is and is emitted to the viewing side, so that red light is emitted.

On the other hand, since the background portion 12 in fig. 2 is a portion where no voltage is applied between the electrodes of the liquid crystal display panel 10 in fig. 1, the linearly polarized light transmitted through the reflective polarizing plate 3 is twisted by 90 degrees when transmitting through the liquid crystal layer 5, and the direction of the vibration plane thereof becomes perpendicular to the transmission easy axis 2a of the absorptive polarizing plate 2. Therefore, the linearly polarized light is absorbed by the absorption polarizing plate 2, and becomes black.

As described above, when the backlight 8 emits light in the configuration of fig. 1, the light of the red LED of the backlight 8 transmits only the portion where the character 11 is displayed, and the character can be displayed with red light in a black background.

Next, a case where the backlight emits no light will be described.

Fig. 3 shows a display state when the backlight is not lit. In fig. 1, if the red LED7 of the backlight 8 does not emit light, a linearly polarized light component having a plane of vibration parallel to the transmission easy axis 2a of the absorbing polarizer 2 transmits through the absorbing polarizer 2 within the external light incident from the viewing side.

Since the display characters 21 in fig. 3 are portions where a voltage is applied between electrodes, not shown, of the liquid crystal display panel 10 in fig. 1, linearly polarized light having passed through the reflective polarizing plate 3 passes through the TN liquid crystal layer 5 without being distorted. Therefore, the linearly polarized light having the vibration plane parallel to the transmission easy axis 2a of the absorption polarizing plate 2 is transmitted through the reflection polarizing plate 3 as it is, and reaches the diffusion layer 6 disposed on the upper surface of the backlight 8.

In the diffusion layer 6, the incident linearly polarized light is merely scattered backward, that is, is diffused only in the direction of the red LED7, and therefore, the diffusion layer 6 does not have a reflection layer exhibiting strong reflection characteristics at the lower portion, and thus, black is displayed.

On the other hand, since the background portion 22 in fig. 3 is a portion where no voltage is applied between the electrodes of the liquid crystal display panel 10 in fig. 1, the linearly polarized light transmitted through the reflective polarizing plate 3 is twisted by 90 degrees when transmitting the liquid crystal layer 5, and becomes a vibrating surface having a direction perpendicular to the transmission easy axis 3a of the reflective polarizing plate 3. Therefore, the light is totally reflected by the reflective polarizing plate 3 and returns to the viewing side as it is. Thus, the background portion 22 becomes a white display of a metallic tone.

In this way, in the non-light-emitting state of the backlight, the portion where the characters are displayed becomes black, and the background portion becomes white.

With this embodiment, the background is in the display state of being reflected by the reflective polarizing plate 3, and therefore the display state can be recognized even when the LED is not emitting light. The conventional absorption polarizing plate can be used as a black background, but according to the present invention, a metal-tone white background can be obtained.

In the present embodiment, although the light source of the backlight is an LED, a fluorescent tube such as a cold cathode tube or a hot cathode tube may be used.

Electroluminescent light may be used if power consumption is a priority over luminance. Since this is a surface light emitter, the entire illumination can be performed with uniform luminance, and the diffusion layer 6 can be omitted.

In this embodiment, although no diffusion layer is disposed between the reflective polarizing plate 3 and the 2 nd substrate 4, if a diffusion layer is disposed therebetween, the specular reflection of the reflective polarizing plate 3 is diffused, and therefore, a soft display is obtained, and the visual dependence is reduced.

In the present embodiment, although the absorption polarizing plate 2 is a normal polarizing plate, if a color polarizing plate using 2-color dye is used, the color can be added to the characters even when viewed with external light.

In the present embodiment, the light source of the backlight 8 is a red LED, but it goes without saying that the same effect can be obtained even with green or blue LED colors.

In addition, although the white diffusion layer is used as the diffusion layer 6 in the present embodiment, a color filter may be used as the diffusion layer 6. Furthermore, if a color filter that transmits a wavelength similar to the emission of the LED and diffusely reflects light is used, the filter absorbs light other than the light, and thus the contrast when viewed with external light can be further improved.

The easy axis 2a of the absorption polarizer 2 in the present embodiment and the long axis direction of the liquid crystal molecules on the viewing side of the TN liquid crystal layer 5 of the liquid crystal display panel 10 may be substantially parallel or perpendicular to each other. The easy transmission axis 3a of the reflective polarizer 3 and the long axis direction of the liquid crystal molecules on the backlight side of the TN liquid crystal layer 5 of the liquid crystal display panel 10 may be substantially parallel or perpendicular to each other.

When any one of the substrates is rotated by 90 degrees, the displayed white-black is inverted.

Example 2

Next, embodiment 2 of the timepiece device according to the invention will be described with reference to fig. 4 to 6.

Fig. 4 is a schematic oblique view showing the configuration of the digital display portion of the timepiece device. In fig. 4, the same reference numerals are given to the same parts as those in fig. 1, and the description thereof will be omitted.

In this embodiment, the STN liquid crystal layer 15 having a twist angle of 180 to 270 degrees is enclosed and sandwiched in the gap between the 1 st substrate 1 and the 2 nd substrate 4 to constitute the liquid crystal display panel 20.

A retardation plate 9 is disposed on the viewing side of the 1 st substrate 1 of the liquid crystal display panel 20, and an absorption polarizing plate 2 is disposed on the retardation plate. On the side opposite to the viewing side of the 2 nd substrate 4, the reflective polarizing plate 3, the diffusion layer 6 constituting the backlight 8, and the red LED7 are arranged as in example 1.

When the retardation plate 9, the absorption polarizing plate 2, and the reflection polarizing plate 3 are disposed on both sides of the liquid crystal display panel 20, the optimum arrangement should be made in consideration of the spectral characteristics and the transmittance, in the arrangement angle relationship between the STN liquid crystal layer 15 and the transmission easy axis 2a of the absorption polarizing plate 2, and the arrangement angle relationship between the STN liquid crystal layer 15 and the transmission easy axis 3a (or the reflection axis 3b) of the reflection polarizing plate 3. In this case, the reflective polarizing plate 3 is disposed so that the transmission easy axis 2a of the absorbing polarizing plate 2 and the transmission easy axis 3a of the reflective polarizing plate 3 are in the same direction, based on the state where black is displayed in the normal state by the conventional configuration of the absorbing polarizing plate instead of the reflective polarizing plate.

Next, the display state of the present embodiment will be described. Fig. 5 shows a display state when the backlight emits light.

When the red LED7 of the backlight 8 in fig. 4 emits light, a linearly polarized light component having a plane of oscillation parallel to the transmission easy axis 3a of the reflective polarizing plate 3 is transmitted through the reflective polarizing plate 3 and enters the liquid crystal display panel 20, out of the light emitted from the red LED 7.

Since the display characters 31 in fig. 5 are portions where a voltage is applied between the electrodes, not shown, of the liquid crystal display panel 20 in fig. 4, the linearly polarized light transmitted through the reflective polarizing plate 3 is transmitted through the STN liquid crystal layer 15 without being distorted, and becomes linearly polarized light having a plane of vibration parallel to the transmission easy axis 2a of the absorptive polarizing plate 2, and is incident on the viewer side through the absorptive polarizing plate. Therefore, the display character 31 is displayed in red.

On the other hand, since the voltage is not applied between the electrodes of the liquid crystal display panel 20 in fig. 4, the background portion 32 in fig. 5 is a portion where the linearly polarized light transmitted through the reflective polarizing plate 3 is distorted when transmitting through the STN liquid crystal layer 15, has a vibration plane perpendicular to the transmission easy axis 2a of the absorbing polarizing plate 2, is absorbed by the absorbing polarizing plate 2, and is displayed in black.

Therefore, when the backlight 8 emits light, the light emitted from the red LED7 of the backlight 8 passes through only the portion of the display character 31 shown in fig. 5, and the character is displayed in red.

Next, a display state when the backlight is not emitting light will be described. Fig. 6 shows a display state when the backlight is not lit.

When the red LED7 of the backlight 8 in fig. 4 does not emit light, a linearly polarized light component having a vibration plane parallel to the transmission easy axis 2a of the absorption polarizing plate 2 transmits through the absorption polarizing plate 2 and enters the liquid crystal display panel 20 within the external light entering from the viewing side.

Since the display characters 41 in fig. 6 are portions where a voltage is applied between electrodes, not shown, of the liquid crystal display panel 20, the linearly polarized light transmitted through the reflective polarizing plate 3 is transmitted through the STN liquid crystal layer 15 without being distorted. Therefore, the light passes through the reflective polarizing plate 3 and reaches the diffusion layer 6 disposed on the upper surface of the backlight 8.

In the diffusion layer 6, the incident linearly polarized light is merely scattered backward, that is, is diffused only in the direction of the red LED7, and therefore, the diffusion layer 6 does not have a reflection layer exhibiting strong reflection characteristics at the lower portion, and thus, black is displayed.

Since no voltage is applied between the electrodes of the liquid crystal display panel 20 in fig. 4, the background portion 42 in fig. 6 is a portion where the linearly polarized light transmitted through the absorbing polarizer 2 is distorted when transmitting through the STN liquid crystal layer 15, and therefore, the linearly polarized light has a vibration plane perpendicular to the transmission easy axis 3a of the reflecting polarizer 3, and is totally reflected by the reflecting polarizer 3 and returns to the viewing side as it is. Thus, the background portion 42 becomes white showing a metallic tone.

Therefore, with the configuration shown in fig. 4, in the non-emission state of the backlight 8, the background portion is of metallic tone, and the portion where the characters 41 are displayed is black.

As described above, with the embodiments of the present invention, since the background is in the display state of the display reflection characteristic, the display state can be viewed even when the LED is not emitting light. In addition, although the conventional absorption polarizing plate is used, the background becomes black, the present invention can be used to make a white background, and display with high contrast can be performed.

The various modifications described in embodiment 1 above can be applied similarly to embodiment 2.

In the 2 embodiments described above, the 1 st polarizing plate disposed on the viewing side of the liquid crystal display panel was defined as 1 absorptive polarizing plate, and the 2 nd polarizing plate disposed on the backlight side was defined as 1 reflective polarizing plate. However, a plurality of polarizing plates may be arranged.

The polarizing plate 1 is not limited to an absorption polarizing plate, and may be a reflection polarizing plate, or may be a combination of an absorption polarizing plate and a reflection polarizing plate.

The 2 nd polarizing plate may be formed by a combination of an absorption polarizing plate and a reflection polarizing plate.

Possibility of industrial utilization

As described above, the timepiece device according to the present invention includes the absorption polarizing plate, the liquid crystal display panel, and the reflection polarizing plate, and can display the time information and the calendar information with sufficient contrast for viewing in both the non-light emission state and the light emission state of the backlight. The invention can be applied to various digital watches such as watches and table clocks, and can greatly improve the easy-to-see property of the display, remarkably reduce the use frequency of the backlight source, and reduce the consumption of the battery.

Claims (6)

1. A timepiece device having: a liquid crystal panel which seals a liquid crystal layer in a gap between a 1 st substrate and a 2 nd substrate, which are transparent and have electrodes formed on opposite surfaces thereof, and displays at least one of time information and calendar information; a 1 st polarizing plate disposed outside the 1 st substrate on the viewing side of the liquid crystal panel; a 2 nd polarizing plate disposed outside the 2 nd substrate; and a backlight disposed on a side of the 2 nd polarizing plate opposite to the viewing side, characterized in that:

the 1 st polarizing plate is an absorption polarizing plate that absorbs linearly polarized light having a plane of vibration perpendicular to a transmission easy axis;

the 2 nd polarizing plate is a reflective polarizing plate that reflects linearly polarized light having a plane of vibration perpendicular to the easy axis of transmission;

the liquid crystal layer sealed in the gap between the 1 st substrate and the 2 nd substrate of the liquid crystal panel is twisted nematic liquid crystal with a twist angle of 90 or less;

the absorption polarizing plate is disposed so that a transmission easy axis of the absorption polarizing plate is substantially parallel to or perpendicular to a long axis direction of liquid crystal molecules on a viewing side of the twisted nematic liquid crystal;

the reflective polarizer is disposed so that a transmission easy axis of the reflective polarizer is substantially parallel to or perpendicular to a long axis direction of liquid crystal molecules on a backlight side of the twisted nematic liquid crystal with respect to the liquid crystal panel.

2. The timepiece device of claim 1, wherein: a diffusion layer is provided on the liquid crystal panel side of the reflective polarizing plate.

3. The timepiece device of claim 1, wherein: the absorption polarizing plate is a color polarizing plate using 2-color dye.

4. The timepiece device of claim 1, wherein: the backlight includes a light source such as a light emitting diode or an electroluminescence light, and a diffusion layer for diffusing light emitted from the light source.

5. The timepiece device of claim 4, wherein: the diffusion layer is formed of a coating film in which silica particles or acrylic resin particles are diffused into a transparent adhesive.

6. The timepiece device of claim 4, wherein: the diffusion layer is a color filter.