JP2002094836A - Data presenting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a function of guiding a position on a data base 1 (stage or mounting surface) to place data to an operator in a data presenting device for reproducing photographed image on a screen or the like out of the device by photographing a document or a cubic object by a CCD camera 3. SOLUTION: A mark projector 2i for projecting a beam on a surface of the data base 1 by scanning mirror means (polygon mirrors) 4c and 4d to generate a guide pattern (grating-like pattern or dot-like pattern) 4e during generating a photographing signal in a blanking section is provided. Thus, the data presenting device 10 capable of dealing with zooming of a photographing lens without reproducing the pattern 4e on the screen or the like and without obstruction by the data on the base 1 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a document presentation device for reproducing a photographed image of a document such as a document or a three-dimensional object on a screen or the like via a monitor device, a projector, or the like.

[0002]

2. Description of the Related Art As one type of audio-visual equipment used in conferences, conferences, exhibitions, and the like, a subject such as a material is placed on a flat stage, and photographed from above while projecting light with a lighting device. 2. Description of the Related Art Document presentation devices that display a captured image of a subject on a screen of a monitor device and project the image on a screen by a projector have been used.

A material presentation device 50 according to the prior art will be described below.
Will be described with reference to FIGS. In FIG. 6 which is an external perspective view of a document presentation device 50 according to the related art, the document presentation device 50 is a document table 51 which is a mounting surface (stage) on which a document such as a document or an entity is placed, and illumination of the document. A projector 52 as a means, a camera (CCD) 5 for photographing the document table 51 from above and outputting a photographed image including the material as an image signal
3. An image processing unit 54 that performs signal processing on an image signal output from the camera 53, and a video output line 55 that outputs an image signal (video signal) output from the image processing unit 54 to the outside of the apparatus.

The photographing lens mounted on the camera 53 may be a short focal length lens having a fixed photographing angle of view, but if it is constructed using a zoom lens having a variable focal length,
The shooting angle of view varies according to the set zoom position, so you can shoot and play back the entire image of a large subject,
Alternatively, a usage method such as enlarging and reproducing a portion of a subject is possible. Further, the arm structure for holding the camera 53 may be configured such that the holding angle of the camera 53 can be changed to change the viewpoint (direction of shooting) of the camera 53.
It is also possible to configure without including the light projector 52.

Returning to FIG. 6, a video signal output from the video output line 55 is input to a monitor device or a video projector device (neither is shown) outside the device, and data is displayed on a display screen or a screen of the monitor device. The configuration is such that the material is presented by reproducing a captured image of the subject on the table 51.

Further, a document presentation device 50 according to the prior art
A more detailed configuration of the material presentation device 50 will be described with reference to FIG.

The document presentation device 50 includes a CCD (Cha).
The imaging device 7a generates and outputs an imaging device output signal as an image signal from an optical image of a subject, and converts an imaging device output signal as an analog signal into a continuous digital signal, which is realized by rge coupled device) or the like, and performs scanning. Pre-processing circuit A / D converter 7 for outputting as an image signal
b, an image processing circuit 7c for arranging scanning image signals, which are continuous digital signals, according to the pixel configuration of the screen to be reproduced and outputting a screen signal composed of predetermined vertical and horizontal pixels.

Further, the material presentation device 50 converts the input screen signal into a D / A converter 7 as a digital video signal in accordance with a timing signal input from the central processing unit 7e.
f, an image rate converter 7d for outputting the digital video signal to an analog video signal which is a moving image signal, and outputting the analog video signal to the outside of the device 50 in accordance with the above-mentioned timing signal for reproduction on a monitor device or the like. And a D / A converter 7f to be provided.

Further, in the document presentation device 50, the central processing unit 7e, which controls the control of the device 50, and the imaging device 7a, when receiving a subject image capturing instruction from the central processing unit 7e, captures an image. And a timing generator 7g for outputting the conversion timing to the pre-processing circuit A / D converter 7b.

The storage element 7j shown in FIG. 7 has a function of storing the above-mentioned screen signal or digital video signal according to a command, and can perform the following operations, for example. That is, when the material on the material table 51 is changed and the user tries to replace the material on the next presentation material, the replacement work is reproduced on the screen as it is, and the quality is poor.
The image signal and the like of the current material are stored in the storage element 7j in advance, and the stored image signal is continuously output during the reloading work. After the work is completed, the photographed image of the next material is output and reproduced on the screen. It is such an operation.

Next, in the conventional material presentation device 50,
The outline of the flow of a signal obtained by photographing a subject will be described with reference to FIG. When the operator of the device 50 instructs the device 50 to reproduce the subject image by pressing an operation button or the like, the central processing unit 7e outputs an image capture command to the timing generator 7g. The timing generator 7g controls the image sensor 7a in accordance with the command to start photographing a subject (not shown) placed on the data base 51.

An analog image signal output from the image pickup device 7a is converted into a continuous digital image signal by a pre-processing circuit A / D converter 7b, and a screen signal in which a predetermined number of pixels are arranged vertically and horizontally by an image processing circuit 7c. Is converted to The converted screen signal is buffered in the image rate converter 7d, and has a D / A converter 7 at a rate determined by the timing signal output from the central processing unit 7e.
and output to the outside of the device 50 as an analog video signal which is a moving image signal.

[0013]

The document presentation device 50 according to the prior art described above has the following problems to be solved. (1) A sign that guides the position where the material should be placed
1 is that the mark itself is photographed by the camera 53 and reproduced on a screen or the like. The camera 53 is configured to take an image of the data base 51 from above and reproduce the captured image on a screen or the like.
Everything within the shooting angle of view above is reproduced. For this reason, the upper surface of the data base 51 has no display and is configured as a plain. On the other hand, when the operator places a document on the document table 51, it is often necessary to provide a marker for guiding the operator to the position to be placed. In particular, if the material is a document, it is hard to see if the material is reproduced while being tilted. Therefore, it is particularly necessary to display a ruler-like mark for regulating the placement position and angle. However, such a mark is not reproduced on a screen or the like, and the material presentation device 5
In the past, it was not possible to provide 0.

(2) The range on the data base 51 where the image is taken by the camera 53 and reproduced is unknown. As described above, the camera 53 that is the photographing unit of the device 50
In some cases, a zoom lens is mounted as a photographing lens, and an arm structure for holding the camera 53 is
There is also a case where the mounting (holding) angle of is changed. Therefore, it is often not uniquely determined which range is photographed and reproduced on the upper surface of the document table 51.

In reproducing the image of the material, there are many uses such as exchanging a plurality of documents one after another according to the order and reproducing the document to prepare a material for a lecture. In such a case, the angle of view is fixed. It is possible to remember the place where the documents were placed on the document table 51 last time and put the documents in the same place next time, but if there is no mark on the document table 51, such work can be done Is often difficult.
Therefore, when reproducing the next document, first,
It is necessary to place the document at an approximate location on the screen 1 and look at the playback position of the document played back on the screen at that time, correct the position where the document is placed, and make it a proper position.

Correcting the position of the document once placed on the document table 51 each time it is replaced is a troublesome task for the person performing the reproduction, and also for the audience watching the reproduction of the document on the screen to listen to the lecture. It was unsightly, exciting, and halved the appeal of the lecture.

(3) When a mark for guiding the place where the material is to be placed is displayed on the material stand 51, the mark is hidden by the placement of the material and becomes invisible. The photographing range corresponding to the photographing angle of view is displayed by printing or the like on the upper surface of the data base 51 as a line, a set of continuous points, or the like, and the operator of the device 50 places the material in the displayed range. In addition, a configuration for performing appropriate reproduction is also conceivable. However, the material placed on the data base 51 is not limited to a small one that fits within the range of the display, but it is naturally conceivable that the display itself may be obscured like a large format document. Could not fulfill its function.

(4) If a mark for guiding the place where the material is to be placed is displayed on the material stand 51, it cannot respond to a change in the angle of view of the camera 53 or the movement of the shooting point. As described above, in a camera having a zoom lens as a photographic lens, the photographic angle of view changes. Therefore, even if the photographic range is displayed on the data base 51, it is not possible to cope with it by displaying only one type of mark. Trying to solve this,
Even if a plurality of marks are displayed on the data base 51 and each of them is intended to correspond to a different shooting angle of view, the operator easily knows which of the plurality of marks corresponds to the current shooting angle of view. I can't do that. Further, since the plurality of guidance marks displayed on the data base 51 are also included in the image taken by the camera 53, the display marks are also reproduced together with the material, and the performance of the device 50 is reduced. The lack of quality is as described above.

Accordingly, the present invention has been made in view of the above-mentioned problems, and particularly, a guide which is a mark for placing a material on a stage during a horizontal or vertical blanking period of a moving image signal output from a photographing means. By providing a projection means for optically projecting the pattern onto the upper surface of the stage, it is possible to provide a mark on the data base (stage) that will not be reproduced on the screen, and to grasp the reproduction range on the stage. It is another object of the present invention to provide a document presenting apparatus capable of coping with a change in an angle of view of a photographing means and a change in a photographing direction without a mark on a stage being hidden by placing the material.

[0020]

In order to solve the above-mentioned problems, the present invention provides a document presentation device having the following configurations (1) to (4). (1) A stage (data base) 1 on which a material to be a subject is mounted, and a photographing means (camera) 3 for generating and outputting a moving image signal (video signal) of the material mounted on the stage 1 In the document presentation device 10 that outputs the moving image signal, a horizontal or vertical blanking period of the moving image signal output from the photographing unit 3 (see FIG.
3b) guide patterns (projection patterns in FIGS. 4 and 5) 4e as marks for placing the material on the stage 1;
A document presentation device 10 comprising a projection unit (mark projection device) 2i for optically projecting 5d onto the upper surface of the stage 1. (2) The photographing unit 3 has a function of changing a photographing angle of view, and the projection unit 2i changes the size of the guide patterns 4e and 5d according to the variable photographing angle of view. The document presentation device 10 according to claim 1. (3) The projection means 2i is a polygon mirror (FIG. 4)
4c and 4d, wherein the guide pattern 4e is projected onto the upper surface of the stage 1 in accordance with the rotation of the polygon mirrors 4c and 4d irradiated with the light beam.
The document presentation device 10 according to claim 1 or 2. (4) The projection means 2i is provided with the guide pattern 5d.
(Diffraction gratings) 5b and 5c for generating the light beam, and projecting the guide pattern 5d on the upper surface of the stage 1 in accordance with the emission of the diffracted light from the diffracting means 5b and 5c irradiated with the light beam. The document presentation device according to claim 1 or 2, wherein:

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to FIGS.
FIG. 1 is an external perspective view of a document presentation device according to a first embodiment of the present invention, FIG. 2 is a block diagram of the device of FIG. 1, and FIG. 3 is a timing chart for explaining the operation of the device of FIG. FIG. 4 is a schematic diagram illustrating the configuration of a landmark projector included in the apparatus of FIG. 1, and FIG. 5 is a second diagram according to the embodiment of the present invention.
FIG. 3 is a schematic diagram illustrating a configuration of a landmark projector included in the document presentation device according to the embodiment of FIG.

First, a material presentation device 1 according to a first embodiment.
0 will be explained.

FIG. 1 is an external perspective view of a document presentation device 10 according to the present embodiment. As shown in FIG. 1, a document presentation device 10
Is a mounting table (stage) 1 as a mounting surface for mounting a document such as a document or an entity, a floodlight 2 for illuminating the document, an image signal of a photographed image including the document by photographing the table 1 from above. (CCD) 3 for outputting image data, an image processing unit 4 for performing signal processing on an image signal output from the camera 3, and an image processing unit 4
And a video output line 5 for outputting a moving image signal (video signal) output from the device to the outside of the device, as in the document presentation device 50 according to the related art described above. Further, the photographing lens mounted on the camera 3 may be a zoom lens, and the arm structure for holding the camera 3 may be capable of changing the holding angle of the camera 3, and may be configured not to include the projector 2. It is the same as the conventional one.

Further, the characteristic configuration of the material presentation device 10 of the present embodiment is that the mark projection device 2i is provided, and the upper surface, which is the material mounting surface of the data base 1, is also a mark projection surface. It is. Details of those configurations will be described later.

Next, the detailed configuration of the material presentation device 10 of the present embodiment will be described with reference to the block diagram of FIG. As shown in FIG. 2, the material presentation device 10 includes an image sensor 2a, a pre-processing circuit A / D converter 2b, an image processing circuit 2c, an image rate converter 2d, a central processing unit 2e, and a D / A converter. 2
f, the timing generator 2g, and the storage element 2j are the same as those of the conventional data presentation device 50, and the functions of these components are the same as those of the conventional configuration.

On the other hand, the material presentation device 10 of the present embodiment is characterized in that it has a timer 2h and the mark projector 2i described above. The timer 2h receives an image capture state signal input from the central processing unit 2e via the synthesizer, and outputs a timer output signal, which is a step signal to be turned off after the ON state has been maintained for a predetermined time, to the landmark projector 2i. Output to The mark projector 2i receives a timer output signal input from the timer 2h, and projects a guide pattern, which is a mark for placing a material, on the upper surface of the data base 1 only while the timer output signal is in an ON state. The details of the projecting operation will be described later.

Next, the transition of changes in signals related to the operation of the timer 2h and the landmark projector 2i will be described with reference to the timing chart of FIG. First, as described above, in the present apparatus, the camera 3 captures an image of a subject on the document table 1 and generates a plurality of continuous screen signals. That is, in the present apparatus 10, a period during which a photographing signal is captured to generate one image (FIG. 3, image capturing 3a), and a blanking period between the image signal and the image signal where there is no photographing signal (image). The processing (projection) 3b) is alternately repeated. The image signal generated and output by the device 10 also has a screen signal section and a blanking section respectively corresponding to those periods. "Blanking period" above
In this embodiment, the vertical blanking period is used. However, it is also possible to use a horizontal blanking period as a different configuration, and this is also included in the present invention. In a configuration different from that of the present embodiment, in which the guide pattern is projected during the horizontal blanking period, 1
Rather than projecting at the interval between the transmission of
It goes without saying that a configuration based on a well-known technique of a television camera may be adopted so that the guide pattern is projected at the scanning and transmission intervals of the horizontal scanning line.

Further, in the present apparatus 10, a pulse-like image capture signal is output from the central processing unit 2e at the start of the video capture period 3a, and is also input to the timer 2h.
The timer 2h operates for a predetermined time equal to the capture time of one screen after the input of the image capture signal (corresponding to FIG. 33a).
After the standby, the timer output signal is changed from the off state to the on state. Further, the timer 2h changes the timer output signal from the ON state to the OFF state when an image capture signal for reading the next screen signal is input. Or timer 2h
May be configured to change the timer output signal to the off state when a predetermined time has elapsed after the on state.

That is, since the timer output signal is in the on state during the blanking period and is in the off state during periods other than the blanking period, the landmark projector 2i always checks the state of the timer output signal, and outputs data only when it is in the on state. By projecting a guide pattern serving as a mark on the upper surface of the base 1, the projected guide pattern is not photographed by the camera 3 and is not reproduced on a screen or the like.

Next, the configuration of the landmark projector 2i will be described.
FIG. 4 is a schematic diagram illustrating a main configuration of the mark projector 2i included in the document presentation device 10 according to the present embodiment. As shown in FIG. 4, the mark projector 2i includes a light source 4a that emits light in synchronization with a timer output signal. The light source 4a includes a light emitting diode that emits light in accordance with a current supplied, a current amplification unit, a switching unit, and the like. It goes without saying that the light emitting source may be constituted by a device other than the light emitting diode. Further, the landmark projector 2i includes a half mirror 4b into which light emitted from the light source 4a is incident, branches in two directions and emits the light, first and second polygon mirrors 4c and 4d driven to rotate around a rotation axis. Contains.

The first polygon mirror 4c uses a straight line perpendicular to the incident direction of light emitted from the light source 4a as a rotation axis,
Rotational driving is performed by driving means and control means (not shown). The second polygon mirror 4d is driven to rotate in the same manner with a rotation axis being a straight line parallel to the incident direction of the light beam.

Each of the polygon mirrors 4c and 4d is
It has a disk-like shape with a thickness and has a plurality of flat reflecting mirrors on the periphery. Further, each reflecting mirror is configured such that the angle with respect to a reference line, for example, a rotation axis is different.

The operation in which the mark projector 2i projects a guide pattern on the data base 1 will be described. The light beam emitted from the light source 4a and incident on the half mirror 4b is a thin beam having a substantially point-like cross section, and is split into two beams by the half mirror 4b.

One of the two beams enters the first polygon mirror 4c, is reflected by one peripheral reflecting mirror, and forms an image on the document table 1 as one point image. Further, at this time, since the first polygon mirror 4c is rotating, the point image on the data base 1 moves in one direction.
The moving point image is recognized as a line image due to the afterimage phenomenon of human vision. (In the projection pattern 4e in FIG. 4, for example, 4e1)

Further, when the rotation of the first polygon mirror 4c advances and the beam hits the reflecting mirror at the next position, the angle of the reflecting mirror is different. In a different position from (4e1),
For example, 4e2 in FIG.

On the other hand, a plurality of line images due to the afterimage phenomenon are also generated on the data base 1 by the beam incident on the second polygon mirror, and the rotation axes of both are orthogonal. As in 4e3 and 4e4, the above (4e1,
4e2) is an orthogonal line image. After all, the rotation of the first and second polygon mirrors 4c and 4d causes a plurality of orthogonal straight lines to be generated on the material mounting surface of the data base 1 by the afterimage phenomenon, thereby forming a lattice-like pattern as a whole. If this lattice pattern is used as a mark for the position where the material is placed, the correct position can be placed, and the lattice pattern will not be reproduced on the screen etc., and it will be projected on the placed material. The grid pattern is not hidden by the data.

In the example shown in FIG. 4, the light source 4a emits light continuously and a lattice-like pattern is generated.
It is also easy to generate a pattern in which dots (dots) are arranged vertically and horizontally by intermittently emitting light. Furthermore, if the light emission interval of the light source 4a is optimally controlled, it is possible to prevent a specific straight line or a specific dot of a dot-like pattern from being projected in the lattice-like pattern 4e shown in FIG. It is possible to change the size of the grid-like or dot-like pattern generated on the table 1 and the position on the surface of the data base 1. In other words, it is easy to generate an optimal guide pattern according to the shooting angle of view and the shooting point by setting in conjunction with the zoom position of the shooting lens, the shooting direction, or separately by the operator.

Next, a material presentation device according to a second embodiment of the present invention will be described with reference to FIG.
The material presentation device of the present embodiment has the same external appearance (perspective view of FIG. 1) and schematic configuration (block diagram of FIG. 2 and timing chart of FIG. 3) as the material presentation device 10 of the first embodiment described above. have. The difference from the first embodiment is that the configuration related to the projection in the landmark projector is different.

In FIG. 5, which schematically illustrates the configuration of the landmark projector of the material presentation device of the present embodiment, the landmark projector includes:
It has a light source 5a composed of a light emitting diode or the like, and two diffraction gratings 5b and 5c into which light emitted from the light source 5a enters and emits diffracted light in a predetermined direction.

The first diffraction grating 5b emits a plurality of beams as diffracted light according to the beam incident from the light source 5a. The second diffraction grating 5c receives a beam emitted by the first diffraction grating 5b, and emits a plurality of beams as diffracted light in accordance with the incidence. For each diffraction grating, the outgoing angle (diffraction angle) with respect to the incident angle of the beam can be freely set in design, and a diffraction pattern determined by the design of each diffraction grating is generated on the upper surface of the data base 1 as a projection pattern.

Further, in this embodiment, the variable power movable lens 3b in the photographing zoom lens included in the camera 3
And the first diffraction grating 5b are configured to interlock and change the position. When the first diffraction grating 5b is at a different position, the diffraction images emitted from the first diffraction grating 5b and generated on the surface of the second diffraction grating 5c also have different sizes. Therefore, the first diffraction grating 5b is configured to move to a different position according to the position of the variable magnification movable lens 3b, and a guide pattern having a size corresponding to a shooting angle of view is formed on the data base 1 by appropriately configuring. Can be generated.

Since the diffraction gratings 5b and 5c are small and lightweight members, the data presentation device including the mark projector can be reduced in size and weight.
It can be configured simply and at low cost. It should be noted that as a configuration different from the above-described embodiment, the diffraction grating has
A configuration is also conceivable in which only a single lens is provided and no interlocking mechanism with the zoom lens 3b is provided. In that case, although there is no function of changing the guide pattern in conjunction with the zooming operation of the taking lens, the configuration is simpler and more reliable. The above configuration is also included in the present invention.

It is to be noted that a feature common to the first and second embodiments is that the position where the mark projector is arranged is determined by the camera 3.
There is a unique effect that it is possible to project onto the document table 1 from an oblique direction away from the camera. In other words, when a landmark projector is realized with a configuration similar to the conventional optical projector using a configuration different from that of the present embodiment, for example, a transparency (a photographic slide, a transmissive material such as an OHP material), a projected image of the transparency is obtained. In order to obtain good quality (which is used for the landmark pattern), the projection direction needs to be perpendicular to the projection plane of the data base 1 in order to maintain the geometric symmetry in the optical arrangement, and thus it is inevitable. It is necessary to arrange a landmark projector near the camera 3. This leads to an increase in the size of the document presentation device, and a large configuration above the device, which may cause inconveniences such as instability during installation.

On the other hand, in the first embodiment of the present invention described above, the beam reflected from the polygon mirror
Since the image is formed by projecting onto the surface of the document table 1, it is sufficiently possible to adopt a configuration in which the image is projected from an oblique direction with respect to the upper surface of the data base 1. The deformation of the projection pattern (so-called trapezoidal distortion) can be sufficiently dealt with by previously deforming the projection pattern in the reverse direction and correcting the shape of the projected image by canceling out the distortion.

Also in the second embodiment, since a guide pattern is generated by a diffraction image, projection from an oblique direction can be sufficiently performed, and the same effect as described above can be obtained.

In the first and second embodiments of the present invention, the projection of the guide pattern onto the stage is performed during the horizontal blanking period or the vertical blanking period of the moving image signal picked up by the image pickup means. In either case, it goes without saying that the effects of the present invention described above are exhibited.

[0047]

As described above in detail, according to the present invention, during the horizontal or vertical blanking period of the moving image signal output from the photographing means, a guide pattern, which is a mark for placing a material on the stage, is optically formed on the upper surface of the stage. By providing a projection means for projecting on the screen, a mark that is not reproduced on the screen can be provided on the data base (stage), and the reproduction range on the stage can be grasped. This provides an effect of providing a data presentation device that can respond to a change in the angle of view of the photographing means and a change in the photographing direction without being hidden by the placement of the photographing means.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a document presentation device according to a first embodiment of the present invention.

FIG. 2 is a block diagram of the apparatus of FIG.

FIG. 3 is a timing chart for explaining the operation of the apparatus shown in FIG. 1;

FIG. 4 is a schematic diagram illustrating a configuration of a landmark projector included in the apparatus of FIG.

FIG. 5 is a schematic diagram illustrating a configuration of a landmark projector included in a material presentation device according to a second example of the embodiment of the present invention.

FIG. 6 is an external perspective view of a document presentation device according to the related art.

FIG. 7 is a block diagram of the device of FIG. 6;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Reference stand (stage) 2i Landmark projector (projection means) 3 Camera (photographing means) 4c, 4d Polygon mirror 4e Projection pattern, grid pattern (guide pattern) 5b, 5c Diffraction grating (diffraction means) 5d Projection pattern, dots Pattern (guide pattern) 10 Document presentation device

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) H04N 1/04 H04N 1/04 Z

Claims (4)

[Claims] 1. A presentation device comprising: a stage on which a material to be a subject is placed; and a photographing means for generating and outputting a moving image signal of the material placed on the stage, and outputting the moving image signal. The apparatus, further comprising: a projection unit for optically projecting a guide pattern, which is a mark for placing the material on the stage, on a top surface of the stage during a horizontal or vertical blanking period of the moving image signal output from the imaging unit. A material presentation device characterized by the following. 2. The apparatus according to claim 1, wherein said photographing means has a function of changing a photographing angle of view, and said projecting means changes the size of said guide pattern in accordance with the variable photographing angle of view.
Document presentation device described. 3. The projection means comprises a polygon mirror,
The document presentation device according to claim 1, wherein the guide pattern is projected on the upper surface of the stage in accordance with rotation of the polygon mirror to which the light beam is applied. 4. The projection means includes a diffraction means for generating the guide pattern, and the projection means projects the guide pattern onto the upper surface of the stage in accordance with the emission of the diffracted light from the diffraction means irradiated with the light beam. The document presentation device according to claim 1, wherein the document presentation device is characterized in that: