HK1080801A - Projection-area dependent display/operating device - Google Patents

Description

Display/operating device depending on projection surface

Technical Field

The invention relates to a display and/or operating device for controlling a machine, comprising a projection device for projecting an image onto a projection surface, a detection device for scanning the projection surface, and a control computer for controlling the projection device and the detection device.

Background

Today, when operating printing presses, the operator must keep a number of operating elements and displays, which are distributed over several locations of the printing press, in line of sight. For this reason, printing press consoles mostly have an image display screen, by means of which the most important adjustments to the printing press can be made. In addition, a sheet rack is usually provided next to the display screen, wherein further operating elements, for example for adjusting the inking zone of the printing press, are arranged around the sheet rack. In addition, the functions of the printing press can only be operated by further operating elements, for example on the individual printing units, on the feeders or on the delivery unit. In this way, the operating elements of the printing press are distributed over different locations and therefore cannot always be operated very simply, since only the main display on the control console of the printing press has the corresponding auxiliary functions which are not available for the operating elements on the individual printing units.

In recent years, new operation schemes are continuously developed, and the working principle of the virtual touch screen also exists. One such virtual touch screen is known from DE 19951322 a1, which does not require a surface that is sensitive to touch. In this case, an operator can touch and control the projected operator interface with his/her finger by projecting an operator interface onto a predetermined surface by means of a projector. If the user points with his finger at a switch surface of the virtual operating interface, the position of the user's finger is recorded with a camera after a predetermined minimum duration instead of the touch-sensitive sensor and is processed by computer.

In this way, the operator can control the device via the virtual operating interface without having to have an actual touch screen.

A similar solution is sought in DE 10007891 a1, which describes an interactive window of a shop. Here, a projector is provided on the inside of the shop window, which projects an operating surface from the inside onto the shop window glass, so that the operating surface can be seen by the pedestrians. If the pedestrian touches the individual operating elements of the operating surface with his fingers, the pedestrian's touch is detected by means of the camera and transmitted to a computer. The projector image is changed according to the touched operation element. The position of the finger is also calculated here by camera analysis, without actually touching the viewing window, it being sufficient if the finger is close and its position can be clearly recognized.

However, the two cited patent applications have drawbacks, namely: the operating surface can only be projected onto a fixedly predefined surface. Here, no transformation of the projection surface is considered.

Disclosure of Invention

The object of the present invention is to provide a display and/or operating device which can also be used to implement functions in the case of a change of projection surface.

According to the invention, a display and/or operating device for controlling a machine is proposed, comprising a projection device for projecting an image onto a projection surface, a detection device for scanning the projection surface, and a control computer for controlling the projection device and the detection device, wherein the projection surface can be analyzed by means of the detection device and the control computer, and the content of the image to be projected can be controlled by the control computer as a function of the analysis of the projection surface.

The invention also comprises a projection device by means of which the image or the operating surface is projected onto an arbitrary projection surface. In a rational manner, the projection device is a video projector or data projector, which is connected to a control computer. Furthermore, as in the prior art, a detection device is connected to the control computer, by means of which an image projected onto the projection surface or the operating surface can be detected. In contrast to the prior art, however, a camera suitable for this purpose as a detection device not only processes the operator's touch on a specific element of the projected image or operating surface, but also analyzes the projection surface itself. In this way, for example, in the case of a very dark projection surface, the detection device and the connected control computer can ensure that the projected images do not contain dark color components, since they cannot be seen on the dark projection surface. Furthermore, the content of the projected image or of the projected operating surface automatically changes as a function of the projection surface characteristics, that is to say the appearance image of the projected image or of the operating surface changes as a function of the projection surface characteristics. If this image is projected, for example, onto the sheet surface on a sheet support of a printing press control, the projected image differs from the image in the case of a completely white sheet, if the sheet is already printed. The display, for example for ink zone control, is not visible on white sheets, since this makes sense only if the sheet has already been color-printed.

In a first embodiment of the invention, it is provided that the image is an operating surface. In this way it is possible to achieve: the projected image not only replaces the display means of the image display screen but also provides all the functions of the touch screen display, that is to say the operator can touch the operating elements of the projected image with a finger and trigger the corresponding functions as when using a touch screen. Thus, the projected image can be used as an equivalent value of an operating surface.

In addition, it is advantageously provided that the operating surface can be projected onto a printing material of a printing press. In order to be able to fine-tune the adjustment of the printing press after the first test printing, a test sheet is usually placed on a rack next to the printing press control console and evaluated by the printer. If the printed image is not satisfactory, the adjustment of the printing press must be modified accordingly. The device according to the invention now makes it possible to project the operating surface for modifying these adjustments directly onto the print substrate and to directly correlate the individual operating elements of the operating surface with the print substrate. Thus, the printer no longer has to be directed to an additional operating desk or display screen, but the operating surface and the print substrate are directly in front of the other.

In a further advantageous embodiment of the invention, it is provided that the operating surface can be projected onto a printed substrate, and the image of the operating surface can be changed by the control computer as a function of the properties of the substrate. In this case, the color of the printed substrate is first taken into account, and the operating surface is adapted, for example, in such a way that: in the very dark regions of the print substrate, there are no operating elements, since there they are difficult or even impossible for the printer to see. This makes it possible, for example, by the control computer to arrange the individual control elements differently on the control surface, so that the control elements and the display are located only in bright areas. Furthermore, the operating surface can be automatically adapted to the format of the printing material, since smaller sheet formats govern, for example, fewer ink zones than larger sheet formats. Then, only those ink areas actually present on the sheet are displayed if the sheet size is small. In this way, the operator is only exposed to the operating elements that are actually necessary to modify the print substrate that is located directly in front of it.

Furthermore, it is provided that the projection device and the detection device are located on the same side of the projection surface. In this way, the image can also be projected onto an opaque surface, for example the side wall of a printing press.

In a further embodiment of the invention, it is provided that the projection device is located on the side of the projection area and the detection device is located on the side of the projection area. In this way, for example, the placement surface of the sheet placement support can be made of glass or another transparent material, so that the operating surface can be projected from the interior of the sheet placement support onto the sheets lying on the glass placement surface by means of a projector mounted there. The printer can also see the operating surface if the sheet of printing material is not completely opaque. In addition, this configuration has the advantage that the projector inside the sheet rack can be protected from soiling.

Furthermore, it is provided that the operating surface changes as a function of the operating element touched or operated on the operating surface. If the printer wants to change the setting of the individual ink zones, he can additionally see inserted help text when touching the ink zone display projected onto the substrate, which help text makes it easier for him to adjust the individual ink zones. Furthermore, when touching the operating elements for adjusting the ink zones, a respective sub-menu can be opened and projected onto the print substrate, so that the operator is provided with further operating elements and with further adjustment possibilities. This embodiment of the invention is always particularly advantageous when a plurality of submenus or other operating elements are followed by an operating element, that is to say when an integrated adjustment process is present. In order not to confuse the operator, these further adjustment possibilities are only visible if the operator first performs a basic preselection by touching.

Furthermore, it is provided that the modification to be carried out on the operating surface can be described on the projection surface by means of the projection device. If the printer for example adjusts the value of the opening of the individual ink zones, he knows how these modifications made actually appear on the printed image. The control computer can now compare these modifications made to the printed sheets scanned by means of the camera and then influence the image of the projection device in such a way that these modifications to the inking zone are actually visible on the print substrate. That is, a projection image is superimposed on the print substrate, so that the superimposition of the projection image with the print substrate actually placed in front corresponds to the adjustment of the print of the printed print substrate with the modified ink zones. If the operator is not satisfied with the modifications made, he can re-modify the ink zone adjustments without any problem, without having to first perform a trial print. This saves wasted pages because it is not necessary to perform a trial print each time the adjustment is modified to verify the result of the modified adjustment.

In a further embodiment of the invention, it is provided that the actuating element for the register adjustment is activated by touching an alignment mark on the printing sheet as the projection surface. In this configuration of the invention, the printer does not need to know the overall menu structure of the operating surface in detail any more, but simply touches the register marks of the register adjustment he wants to initiate, and then projects this register adjustment for him by the projection means onto the sheet. When the register adjustment is completed, the operating surface disappears again, so that the image of the printed sheet is no longer disturbed. That is, the printer can simply call up the individual operating elements of the operating surface by touching the surface on the substrate sheet on which the modification adjustment is effected. Thus, a very simple, comfortable and yet at a glance operation for the printer is created.

Furthermore, it is provided that the inking zone adjustment on the printing press is initiated when a color measuring strip of the sheet to be printed is touched as a projection surface. This represents yet another possibility: only those operating elements which are exactly required by the operator are inserted. The operating surface can thus also be constructed: only when the corresponding location on the sheet is touched, the sheet on the rack next to the printing press is provided with the operating element. Otherwise, the operator sees only the printed sheet, without the impression of a change in the appearance of the sheet being produced by the insertion of the operating element. Since the color measuring strip is used to control the color of the printed ink, it makes sense to associate the initiation of ink zone adjustment with the touching of the color measuring strip.

In a similar embodiment of the invention, it is provided that the measured values can be projected onto the actual measured positions of the sheets used as projection surfaces. In addition to the ink zone opening adjustment, which is usually displayed by means of a graphic bar chart, the spectral measured values can also be displayed, wherein these spectral measured values are digitally inserted precisely at the position on the printed sheets where they are measured. Therefore, the measured values can correspond to the measured points on the printed sheet one to one in place.

In a further embodiment of the invention, it can be provided that the device is portable. The inventive display and/or operating device can thus be used not only for controlling the machine, but also for maintenance purposes. If maintenance is to be performed on a certain part of the machine, the maintenance person can use the device according to the invention to project an image onto that part of the machine where maintenance is to be performed. With the aid of the camera and the model of the machine to be maintained, which is stored in the control computer, maintenance instructions can be inserted in a context-dependent manner, in particular in a projection plane. If the operator touches a certain signal cable, for example, a text can be inserted by means of the projection device depending on the context, which text specifies the task, function or voltage level of the cable to which it belongs. In this way, the maintenance person does not have to recognize it by means of the circuit diagram, but can easily call up the corresponding information by means of the device according to the invention.

It is furthermore advantageous that possible functions of the projection surface can be detected by means of the detection device, which functions are included together by the control computer in the output section of the projection image. In addition to the cables already mentioned, operating elements which are fixedly installed in front of the site can also be considered, so that the maintenance person can be assisted additionally when touching these fixedly installed operating elements by means of text inserted by means of the projection device, making his work easier. Since it is not possible to connect every operating element on the machine to the operating screen, additional information can also be provided there for maintenance personnel or operators by means of the portable device and taking into account the functions which the projection surface may have. In this way, the actual operating elements can be supplemented by the inserted virtual operating surface.

Furthermore, it is advantageous if the size of the sheets lying on the rack can be sensed by the control computer and the size of the projected image can be adapted automatically to this. The size and position of the sheets are sensed, for example, by one or more optical or touch-sensitive sensors in the surface of the rack. The measured sheet size is then transmitted to the control computer, so that the projector accordingly provides a projection image in accordance with the sheet size. This prevents the portion of the rack where no sheet is placed from being illuminated. Thereby avoiding unnecessary reflections.

In a further embodiment of the invention, it is provided that a color test light for illuminating the sheets located on the support is provided, which is connected to the control computer. In order to visually evaluate the printed sheets by the printer, color test lamps are necessary. The color test lamp emits a standard light for this purpose, so that the printer can test the printed sheet for correct color reproduction. However, this light must be switched off during projection, since otherwise the projected image on the printed sheet cannot be seen clearly. Therefore, the control computer must coordinate the color checking lamps and the projected image into use. This coordination may be performed by: the color check lamp is turned off and the light is turned down, or the light path of the color check lamp is interrupted or turned.

It can also be provided that the projector and the color check lamp are combined to form a projection lamp. It is particularly advantageous here if it consists of only one projector which can project images, but also emits monochromatic light for evaluating the color of the printed sheets. The projector also functions as a color check lamp as a projection lamp. Such a function can be achieved by means of a highlight video projector. The advantage of this combination is that the illuminated face of the color check lamp can also be controlled according to specifications, compared to the present solutions. Thus, one color checking lamp/display can be adapted to all machine specifications, for which the illuminated face can be adapted to the corresponding print specifications of a continuously advancing print job. The color of the light can be selected arbitrarily. The amount of light projected onto the sheet can be controlled. Another advantage of such a combination is that the inner part of the projected image, i.e. the part of the image projected onto the substrate, uses white-colored collimated light for illuminating the sheet around which (on the sides as well as above and below) the corresponding display and operating elements can be projected.

Drawings

The invention will now be explained and explained in detail with the aid of a number of figures. The figures show that:

FIG. 1: a printing machine sheet placing frame, a projection device is arranged in front of the sheet placing frame, a camera is arranged above the placing frame,

FIG. 1 a: a top view of the sheet placement frame, with inserted virtual operating elements,

FIG. 2: a printed sheet placing rack with a color inspection lamp, wherein, a projector is arranged in the placing rack and below the transparent projection surface,

FIG. 2 a: figure 2 is a top view of the rack,

FIG. 3: a sheet placing frame, wherein a combined projection lamp and a camera are arranged above the placing frame,

FIG. 3 a: figure 3 is a top view of the rack,

FIG. 4: a printed sheet placing rack, wherein the projection device is arranged at the back of the placing rack and is additionally provided with a touch screen,

FIG. 4 a: figure 4 is a top view of the rack,

FIG. 5: a printing machine equipped with a portable device according to the invention,

FIG. 6: according to the help text inserted by the projection surface for supporting the maintenance personnel,

FIG. 7: a sheet rack, wherein the projection device and the camera are arranged above the rack and additionally projected on the wall behind the rack,

FIG. 7 a: figure 7 is a top view of the projected image,

FIG. 8: a sheet rack, wherein the projector is arranged above the rack, the camera is arranged behind one wall and projects the image onto one wall behind the rack,

FIG. 8 a: figure 8 is a top view of the projected image,

FIG. 9: a sheet placement frame, wherein a rear projection device is arranged behind a wall, a camera is arranged above the placement frame and projects onto the wall behind the placement frame,

FIG. 9 a: figure 9 is a top view of the projected image,

FIG. 10: a sheet rack, wherein a rear projector and a camera are arranged above the rack and behind a wall, projected onto the wall behind the rack,

FIG. 10 a: FIG. 10 is a top view of the projected image.

Detailed Description

Fig. 1 shows a sheet-receiving rack 7, which is provided with a display and operating device according to the invention, next to the control panel of the printing press 1. For this purpose, the sheet-processing rack 7 has a control computer 9 which can be connected in communication with a video and data projector 5 and a camera 4. The communication can be effected here by wire connection or by wireless transmission. The projector 5 is located on the front side of the sheet rack 7, where a printer or other operator normally stays. An arbitrary image 3 can be projected by means of the projector 5 onto the projection surface 6 of the sheet holder 7. The projection surface can be the placement surface of the placement frame 7, but it can also be the surface of a blank or printed sheet 16. The projection surface 6 is scanned by a camera 4 mounted above a sheet holder 7 in order to adapt the image 3 projected onto the projection surface 6 to various circumstances.

In fig. 1a, a top view of the sheet-fed sheet-holder 7 can be seen from above, so that the projected image 3 can be seen on the projection surface 6, which image in this case consists of a plurality of operating elements 12 distributed over the projection surface 6. These operating elements 12 are projected by the projector 5 onto the projection surface 6, so that an operator can initiate an adjustment process on the printing press 1 by touching the operating elements 12 on the projection surface 6. If the operator touches a "Plus" key of the projection on the projection surface 6 shown in fig. 1a, this is recognized by the camera 4 and transmitted to the control computer 9. The control computer 9 then again outputs corresponding control signals to the printing press 1 in order to generate corresponding control processes there. If a printed sheet 16 is placed on the sheet support 7, the projection image 3 is modified in such a way that the virtual operating element 12 shown in fig. 1a is also recognizable on the sheet 16 which is used as the projection surface 6. For this purpose, for example, the color display of the operating elements 12 is adapted accordingly, or in the case of a dark background the arrangement of the operating elements 12 is changed in such a way that these operating elements 12 are again located in the visible range. This is necessary, for example, when the black area is large. Instead of or in combination with the operating elements 12 shown in fig. 1a, it is also possible to insert measured values measured by a measuring device 13 mounted above the sheet-receiving station 7. One such measuring device 13 can be used, for example, for the spectral measurement of printed sheets 16. The measured values obtained can then be displayed on the projection surface 6 directly at the points where they were actually measured on the sheet 16. In this way, the measured values and the measurement locations on the sheet 16 can be directly assigned to one another.

Above the support frame 7, a color test lamp 14 is additionally arranged, which ensures a standard ink temperature of 5000 ° kelvin in most cases for visual evaluation of the printed sheets 16 on the support frame 7. The color testing lamp 14, the projector 5 and the camera 4 are connected to the control computer 9 in order to be able to coordinate the projection of the image 3 in particular with the light of the color testing lamp 14. Since the color check lamp 14 must be turned off in order to project the image 3, otherwise the printer cannot see the image 3.

Fig. 2 shows a modified embodiment of the sheet-fed printing press stand 7 from fig. 1, in which the projector 5 for generating the projection image 3 is mounted inside the sheet-fed printing press stand 7 and illuminates the projection surface 6 from below. If a less thick, light-permeable sheet 16 is used, the operator can still recognize the projected image 3 shown in rear projection with a correspondingly strong projector 5. Here, it is expedient if the sheet-receiving surface of the sheet-receiving rack 7 is made of a transparent material which is transparent to light in order to allow rear projection. Since in the embodiment according to fig. 2 the projector 5 is located inside the sheet holder 7, it is optimally protected from external influences, which can lead to a longer service life of the projector. Furthermore, in the embodiment according to fig. 2, the camera 4 is located above the sheet holder 7 in order to be able to scan the projection surface 6. As can be seen in fig. 2a, the emerging image of the projected image 3 is substantially unchanged for the operator compared to fig. 1 a. Only the color is of course reduced by the rear projection.

Fig. 3 shows another possibility for installing the projector 5, where the projector is installed above the sheet-fed offset printing press stand 7 in the rear area facing away from the operator. This reduces the shadow that the operator produces on the plane of projection 6 when bending over the sheet rack 7. The projector furthermore relates to a special projection lamp 15, which comprises both a projector 5 and a color check lamp 14. The projector 15 can also consist of only one special high-intensity video projector, which can be used not only for projection but also for illuminating the sheets 16 on the support 7 in such a way that the video projector emits monochromatic test light for standard illumination of the sheets 16. The sheet 16 can be illuminated automatically according to specifications, i.e., the rectangular light cone of the projection lamp 15 is automatically adapted to the size of the sheet 16 by means of a sensor. As can be seen in fig. 3a, the projection image representation on the sheet placement frame is also substantially unchanged in this embodiment.

In the embodiment according to fig. 4, the projector 5 is located closer to the sheet holder 7 than in the embodiment according to fig. 3, which in turn further reduces the shadows that can be caused by the operator. In addition, a control station 8 is provided, by means of which the adjustment can likewise be carried out on the printing press 1. The control panel 8 can be, for example, a conventional touch screen currently used in the printing press 1. In the same way, the virtual operating element 12, which is shown on the projection surface 6 in fig. 4a, can be seen on the additional operating table 8. The user can thus make modifications either directly on the projection surface 6 or on the operating table 8. The console 8 is also connected to a control computer 9 which receives and coordinates input data from the console 8 and operator input data detected by the camera 4. At the same time, those modifications made on the projection surface 6 also act on the console 8, and vice versa. Thus, the operator always has the same operating surface in front of him, whether operating with the operating table 8 or with the projected operating surface 3 gives priority.

In fig. 5, a portable configuration of the invention can be seen, which is composed of a portable projector 5 and a portable camera 4. The camera 4 and the projector 5 are preferably accommodated in a single housing, so that the coordination of the detection camera 4 and the projector 5 is easier. The housing is a truly portable device 11. In fig. 5, a portable device 11 may be used to facilitate maintenance of the printing press 1. The printing press 1 shown in fig. 5 has two printing units 2, which are equipped with side wall sheeting. Now, the maintenance person can place the portable device 11, which is composed of the camera 4 and the projector 5, in front of the side wall of the printing unit 2, so that the projected image 3 is projected onto the side wall of the printing unit 2, which serves as the projection surface 6. The portable device 11 is connected to the computer 9 either wirelessly or by a wired connection, or the computer 9 is also integrated in the portable device 11. On the computer 9, a model of the printing press 1 is stored which can be compared with the data detected by the camera 4, and if the camera 4 detects certain actual operating elements on the side wall of the printing couple 2, these operating elements are compared with the data stored on the computer 9 of the portable unit 11, providing support for the operator by integrating corresponding help text into the projected image 3. Here, however, the camera 4 can detect not only the actual operating elements but also all other replaceable or movable components of the printing press 1, provided they are stored in a model on the computer 9 of the portable device 11. Thus, it is possible to assist the maintenance personnel in detaching the roller by: the camera 4 automatically recognizes the roller to be removed and informs the maintenance personnel which roller is involved by means of the projected image 3, and furthermore gives further support for mounting and dismounting. The inclusion of this support makes the portable device 11 fundamentally different from conventional wireless remote control operations, by means of which the operator can also make its adjustments from every arbitrary position on the printing machine 1. However, the wireless remote control operation cannot take into account adjustment modifications made by maintenance personnel on the printing press 1. In addition, wireless remote operation cannot provide support corresponding to a location because it lacks the detecting device 4.

Fig. 6 also shows this, in which the voltage of certain electronic components on the printing press 1 is checked. Because electronic components are most similar and often tightly packed in narrow spaces, it would be valuable to maintenance personnel if he were able to more easily properly arrange the electronic components. The portable device 11 of fig. 5 is also helpful in this respect in that it can, for example, observe the current position of the test tool 10 for detecting the voltage by means of the camera 4 and provide corresponding information about the component that is being touched to the maintenance personnel by means of the projection image 3. Thus, the maintenance person does not have to look at the circuit diagram in the operation manual. If the maintenance person touches a component with the inspection tool 10, the maintenance person can additionally be informed by the projection image 3: which maintenance work is to be performed on the component in addition to detecting the voltage.

Fig. 7 shows a further embodiment. Here, the projector 5 and the camera 4 are located above the sheet rack 7. The projector 5 simultaneously projects the image 3 onto the surface 6 of the sheet rack 7 and the surface 6 of the rear wall behind the rack 7. Thus, two operative surfaces 3 can be projected, wherein these operative surfaces may even be different if the projector 5 is designed as a dual unit with two objective lenses for projecting different images simultaneously. One such projector 5 may for example consist of two conventional video projectors. If the projector has only one unit, the image 3 on the surface 6 is identical, wherein the second image 3 is generated by an optical deflection unit, for example a mirror. Of course, in this embodiment, the image 3 on the rack 7 may be eliminated and only the image 3 may be projected on the rear wall of the rack 7. Fig. 7a shows the image 3 in fig. 7.

The embodiment in fig. 8 differs from the embodiment in fig. 7 in that the camera 4 is located behind the rear wall of the placement frame 7, on which rear wall it projects. For this purpose, the surface 6 and the rear wall itself must be transparent, wherein in fig. 8, as in fig. 7, a double projection is also possible. Here, fig. 8a also shows image 3 in fig. 8.

The further embodiment shown in fig. 9 differs from the embodiment in fig. 8 in that the camera 4 and the projector 5 exchange positions. Here, the projector 5 is located behind a light-transmissive rear wall of the rack 7, and the camera 4 is located above the rack 7 in front of the rear wall. Here, fig. 9a also shows image 3 in fig. 9.

The embodiment shown in fig. 10 differs from the embodiment in fig. 9 in that both the camera 4 and the projector 5 are located behind the light-transmitting rear wall of the placement frame 7. Here, fig. 10a also shows image 3 in fig. 10. Of course, the various possibilities indicated for positioning the camera 4, the measuring device 13 and the projector 5 can be combined with different embodiments of the projector 5 itself, namely as a combined projection lamp 15 or in combination with a color test lamp 14.

List of reference symbols

1 printing press 9 control computer

2 printing device 10 inspection tool

3 projection image 11 Portable device

4 camera 12 operating element

5 projector 13 measuring instrument

6 projection surface 14 color inspection lamp

7 printed sheet placing rack 15 projection lamp

8 operating floor 16 printing

Claims (19)

1. Display and/or operating device for controlling a machine (1), comprising a projection device (5) for projecting an image (3) onto a projection surface (6), comprising a detection device (4) for scanning the projection surface (6) and comprising a control computer (9) for controlling the projection device (5) and the detection device (4), characterized in that the projection surface (6) can be evaluated by means of the detection device (4) and the control computer (9), and in that the content of the image (3) to be projected can be controlled by the control computer (9) as a function of the evaluation of the projection surface (6).

2. Device according to claim 1, characterized in that the image (3) is an operating surface.

3. Device according to claim 2, characterized in that the operating surface (3) can be projected onto a printing material (16) of a printing machine (1).

4. A device as claimed in claim 2 or 3, characterized in that the operating surface (3) can be projected onto a printed substrate (16), the image appearing on the operating surface (3) being changeable by the control computer (9) in dependence on the properties of the substrate.

5. Device according to one of the preceding claims, wherein the projection means (5) and the detection means (4) are located on the same side of the projection surface (6).

6. Device according to one of the preceding claims, characterized in that the projection means (5) are located on the side of the projection surface (6) and the detection means (4) are located on the side of the projection surface (6).

7. A device as claimed in any one of claims 3 to 6, characterized in that the projection means (5) are located inside a sheet holder (7) below the sheet-receiving surface.

8. A device as claimed in any one of claims 2 to 7, characterized in that the appearance of the operating surface (3) depends on the operating element touched or operated on the operating surface (3).

9. Device according to one of claims 2 to 8, characterized in that the modification made on the operating surface (3) can be described on the projection surface (6) by means of the projection means (5).

10. Device according to one of claims 2 to 9, characterized in that the operating surface (3) is used for controlling a printing machine (1).

11. A device as claimed in claim 10, characterized in that the operating element for register adjustment is activatable by touching an alignment mark on a printed sheet as projection surface (6).

12. A device according to claim 10 or 11, characterized in that the ink zone adjustment on the printing press (1) is activated when a color measuring strip of a printed sheet is touched as the projection surface (6).

13. Device according to one of claims 3 to 12, characterized in that the measured values are projected onto a sheet serving as projection surface (6) at the position where they are actually measured.

14. A device according to any one of the preceding claims, wherein the device is portable.

15. Device according to one of the preceding claims, characterized in that functions which the projection surface (6) may have are detectable by means of the detection means (4), and the control computer includes these functions together in the output section of the projection image (3).

16. Device according to one of the preceding claims, characterized in that the size of the sheets (16) on the frame (7) can be determined by the control computer (9) and the size of the projection image (3) can be adapted automatically to the size of the sheets.

17. Device according to one of the preceding claims, characterized in that a color test lamp (14) for illuminating the sheets (16) on the ramp (7) is provided, which is connected to the control computer (9).

18. A device as claimed in claim 17, characterized in that the projector (5) and the color check lamp (14) are combined to form a projection lamp (15).

19. Printing machine (1) having a device according to one of the preceding claims.