JP2000013571A - Optical printing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve mechanical reliability, to realize miniaturization, to perform the simultaneous exposure of red, green and blue and to shorten the exposure time. SOLUTION: A positive voltage is applied to a control electrode 10, an anode conductor 5 is statically driven in synchronism with it, and the positive voltage is applied to the anode conductor 5 of a light emission part to be a lighting object. The light of a light emission block R passes through a red filter 19R, reflected by a reflection mirror 2B, transmitted through dichroic mirrors 2Ca and 2Cb and made incident on a lens system 3. The light of a light emission block G passes through a green filter 19G, reflected by the dichroic mirror 2Ca, transmitted through the dichroic mirror 2Cb and made incident on the lens system 3. The light of the light emission block B passes through a blue filter 19B, is reflected by the dichroic mirror 2Cb, and made incident on the lens system 3. The light which is made incident on the lens system 3 is converged to a prescribed position on a film 21. Matched with the light emission drive, a print head is moved in a sub-scanning direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical print head used in an electrophotographic printer, a silver halide printer, a level printer, a color video printer and the like for forming a desired image on a writing object such as a photosensitive film. About.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a cross-sectional view illustrating a structure of an optical print head disclosed in Japanese Patent No. 92622.

The optical print head shown in FIG. 6 is movable in the sub-scanning direction by a driving mechanism (not shown), and ZnO: Zn phosphors are applied to three lines, and each of the phosphors faces the respective phosphors. There are three filters of red, green, and blue outside the vessel, and a total of three filters are located adjacent to each filter of the fluorescent tube.
A set of lens systems is provided, and three primary colors of red, green, and blue necessary for exposure are extracted from the light emitted from the fluorescent light emitting tube by the red, green, and blue filters.

[0004] To explain further, the fluorescent light emitting tube 5 as a light source
Reference numeral 1 denotes an envelope 54 in which a box-shaped container portion 53 is sealed on a light-transmitting substrate 52, and the container is evacuated to a high vacuum state.

[0005] On the inner surface of the substrate 52, ZnO:
A light emitting section 55 is formed by applying a phosphor layer of a Zn phosphor. Each light emitting section 55 is composed of a plurality of light emitting dots arranged at a predetermined pitch in the main scanning direction.
The light-emitting units 55 are arranged along the sub-scanning direction.
G and 55B are provided.

[0006] Within the envelope 54, each light emitting section 55R,
A plurality of second control electrodes 56 divided for each light emitting dot are provided below 55G and 55B, and a common first control electrode 57 electrically integrated below the second control electrodes 56. Is provided. Below the first control electrode 57,
A linear cathode 58 is provided along the main scanning direction for each of the light emitting units 55R, 55G, and 55B.

On the outer surface side of the substrate 52, a red filter 59R is provided facing the light emitting portion 55R, a green filter 59G is provided facing the light emitting portion 55G, and a blue filter 59B is provided facing the light emitting portion 55B. Is provided. Each filter 59 extracts three primary colors of red, green, and blue from the emission of the phosphor layer facing the filter. Since the emission spectrum of the ZnO: Zn phosphor has a very wide width, the red, green, and blue filters 59 can extract three primary colors of red, green, and blue.

A lens system 60 is provided above each of the filters 59R, 59G, 59B.
Light from each of the light emitting dots of R, 55G, and 55B passes through each of the red, green, and blue filters 59R, 59G, and 59B, and passes through a lens system 60 provided for each of the filters 59R, 59G, and 59B. Light is condensed at a predetermined position on the color film 61 that is the object to be written.

When driving the optical print head constructed as described above, the light emitting dots of the light emitting portions 55R, 55G, and 55B are sequentially scanned in the fluorescent light emitting tube 51, and the light emitting portions are synchronized with the scanning. Corresponding second control electrode 5
6, a positive image signal is applied. A positive voltage is always applied to the first control electrode 57 to accelerate the electrons, thereby preventing the second control electrode 56 to which a negative voltage is applied corresponding to the non-light emitting portion from missing characters.

Then, the optical print head is moved in the sub-scanning direction indicated by an arrow in synchronization with the emission driving of the fluorescent light emitting tube 51, and the light of each color separated is transferred to the color film 61.
Focus on the same position above. Thus, a desired color image is formed on the color film 61.

By the way, the present applicant has proposed an optical print head disclosed in Japanese Patent Application Laid-Open No. 9-1858, separately from the above-mentioned optical print head.

FIGS. 7 to 10 show an embodiment of the optical print head. The publication also states that red, green,
Two embodiments of a switching mechanism for a filter holder having a blue filter are disclosed, and one of them will be described.

In order to reduce the size of the optical print head, this optical print head has one light-emitting line and one lens system, and switches the red, green and blue filters by moving the filters. Red, green, and blue are written in a time-division manner on a color film to be written.

To further explain, as shown in FIG. 7, the optical print head moves along the sub-scanning direction indicated by the arrow in FIG. 7 with respect to the color film 61 as the object to be written set at a predetermined position. The substrate 62 has a substantially rectangular plate shape.

The base 62 has a fluorescent tube 6 as a light source.
3 and red, green, and
Three blue filters 64 (64R, 64G, 64B)
And a light emitting portion 65 (65R, 65G, 6) of the fluorescent light emitting tube 63.
A single optical system 67 including a lens 66 is provided at a position corresponding to 5B).

As shown in FIG. 8, a pair of guide rods 69, 69 as guide members are provided on the inner bottom of the housing 68 of the optical print head in parallel with each other along a pair of long sides. I have. The base 62 is slidably attached to the guide rods 69,69. The base 62 is made up of the guide rods 69, 6
The direction of movement along 9 is parallel to the sub-scanning direction when writing on the color film 61 with dot light.

As shown in FIG. 10, a mounting hole 70 is provided at a substantially central portion of the base 62 so as to penetrate therethrough. Mounting hole 70
, A fluorescent light emitting tube 63 or a filter holder 71 movably attached thereto. A guide groove 72 for guiding the filter holder 71 is continuously provided in the mounting hole 70, and reaches one edge of the base 62 in the moving direction.

As shown in FIGS. 8 and 9, a motor 73 as a means for moving the base 62 is mounted on the inner bottom of the housing 68. The motor 73 is provided near one end of one of the guide bars 69 outside the moving range of the base 62. The drive shaft of the motor 73 is orthogonal to the guide rod 69, and a drive pulley 74 is attached to the drive shaft. Outside the moving range of the base 62, one of the guide rods 6
A driven pulley 75 is rotatably mounted in the vicinity of the other end of 9. The rotating shaft of the driven pulley 75 is a motor 73
And the driven pulley 74 and the driven pulley 7
A drive belt 76 is wrapped around 5. When the motor 73 is driven to circulate the drive belt 76, the base 62 fixed to the drive belt 76 is guided by the guide rod 69 and moves in the sub-scanning direction.

As shown in FIG. 7, a fluorescent light emitting tube 63 as a light source is mounted on a base 62. Fluorescent tube 6
Reference numeral 3 denotes a substantially rectangular parallelepiped envelope 79 which is formed by sealing a box-shaped container portion 78 to a translucent rectangular substrate 77 and evacuated to a high vacuum state.

As shown in FIG. 7, on the inner surface of the substrate 77,
A light emitting portion 65 (65R, 65G, 65B) in which a number of light emitting dots are arranged in a line along the longitudinal direction of the substrate 77 is formed. The light-emitting dots constituting the light-emitting portion 65 are composed of dot-shaped anode conductors provided in a row on the substrate, and a phosphor layer applied to each anode conductor. Each light emitting dot 65R,
The anode conductors of the envelopes 7G and 65B are independent of each other.
9 and driven statically by applying drive signals independently of each other.

The phosphor layers of the light emitting dots of each of the light emitting portions 65R, 65G, 65B are made of ZnO: Zn phosphor. The direction in which the light emitting dots are arranged in the light emitting section 65 is parallel to the main scanning direction when writing is performed on the color film 61 with dot light.

In the envelope 79, on the substrate 77 on both sides of the light emitting section 65, a band-shaped plane control electrode 80 made of an aluminum thin film or the like is provided. When the fluorescent light emitting tube 63 is driven, a positive voltage is applied to the flat control electrode 80 to attract electrons to the light emitting section 65. In the envelope 79, a linear cathode 81 as an electron source is provided below the light emitting section 65 along the main scanning direction.

As shown in FIG. 10, the base 62 is provided with a filter holder 71 which can move relative to the fluorescent tube 63 in the sub-scanning direction. Filter holder 7
Reference numeral 1 denotes a member integrally provided with a rectangular main body 82 slidably engaged with the mounting hole 62a of the base 62 and a rectangular abutting piece 83 engaged with the guide groove 72 of the base 62. . The filter holder 71 is movable in the sub-scanning direction with respect to the mounting hole 62a and the guide groove 72 of the base 62.

As shown in FIG. 10, at one edge of the guide groove 72 of the base 62, two fixed bearings 84 as guide means are provided rotatably at predetermined positions. Guide groove 7 of base 62 facing two fixed bearings 84
2 is provided with a movable bearing 85 as a guide means.
Is provided.

The movable bearing 85 is rotatably provided at the upper end of the support shaft 86. The support shaft 86 has an intermediate portion attached to the base 62 with a shaft 87, and is rotatable within a predetermined rotation angle range in a plane parallel to the main scanning direction. The lower end of the support shaft 86 protrudes downward from the lower surface of the base 62. A spring 8 as an urging means is provided inside the base 62.
8 is held inside, and urges a portion of the support shaft 86 on which the movable bearing 85 is provided above the shaft 87 toward the filter holder 71 side.

The abutment piece 83 of the filter holder 71
It is guided in the sub-scanning direction by being sandwiched between the fixed bearing 84 and the movable bearing 85. A projection 89 is provided on the lower surface of the abutting piece 83. The projection 89 is inserted through the through-hole 90 provided in the guide groove 72 of the base 62, and
2 protrudes downward from the lower surface. A spring 91 is provided between the lower end of the protrusion 89 projecting below the base 62 from the through-hole 90 and the axis of the fixed bearing 84 as a biasing means. The spring 91 holds the filter holder 71
The abutment piece 83 is urged in a direction to protrude outward from the guide groove 72. Movable bearing 85 of butting piece 83
The notch 92 (92a, 92a)
b, 92c) are formed. The movable bearing 85 selectively engages with one of these notches 92, and the filter holder 71 is selectively set at one of three positions with respect to the base 62.

A red filter 64R, a green filter 64G, and a blue filter 64B are respectively attached to the main body 82 of the filter holder 71. Each of the filters 64 is provided at three positions where the filter holder 71 is selectively set.
The positions of R, 64G, 64B and the light-emitting portion 65 of the fluorescent light-emitting tube 63 coincide with each other.

As shown in FIG. 10, a contact portion 93 for contacting the abutting piece 83 of the moving print head is provided with a housing 68.
Is installed at a predetermined position on the inner bottom. When the abutment piece 83 of the filter holder 71 is abutted against the contact portion 93 by moving the base 62 of the print head, the filter holder 7
1 moves in the sub-scanning direction with respect to the base 62, and can position a desired filter on the light emitting section 65 of the fluorescent light emitting tube 63.

As shown in FIG. 10, a locking piece 94 that engages with the lower end of the support shaft 86 of the movable bearing 85 of the moving print head is installed at a predetermined position on the inner bottom of the housing 68. The print head base 62 is moved away from the contact portion 93, and the support shaft 8 of the movable bearing 85 is moved.
When the engaging member 6 is engaged with the locking piece 94, the support shaft 86 rotates about the shaft 87, and the movable bearing 85 moves away from the notch 92 of the filter holder 71. As a result, the filter holder 71 moves toward the contact portion 93 by the urging force of the spring 91, and the movable bearing 85 engages with the notch 92a farthest from the contact portion 93. With this position as the reset position, the red filter 64R is set for the light emitting section 65 of the fluorescent light emitting tube 63.

In the optical print head configured as described above, the fluorescent light emitting tube 63 is driven based on each image signal of an image separated into three primary colors, and the print head is sub-scanned in synchronization with this drive. Move in the direction. At this time, the light emitting portion 65 of the fluorescent light emitting tube 63 of the print head has a primary color filter 64 (red, green,
Any of the blue filters 64R, 64G, and 64B) is set. Perform the above operation for each of the three primary colors,
The three images separated into the three primary colors are overwritten on the photosensitive surface of one color film 61 and written.

Specifically, first, the print head is set at a position (start position) farthest from the contact portion 93 within the movement range. The print head support shaft 86 engages with the locking piece 94 and rotates about the shaft 87, and the movable bearing 85 moves away from the cutout 92 of the filter holder 71. The filter holder 71 is set at a reset position by a spring 91, and a light emitting portion 65 of the fluorescent light emitting tube 63 has a red filter 64R.
Is set. Then, while moving the print head toward the contact portion 93 along the sub-scanning direction, the fluorescent light emitting tube 6 is moved.
3 is driven by a drive signal corresponding to a red image, and the color film 61 is exposed by a red filter 64R.

After the exposure by the red filter 64R is completed, when the print head is further moved toward the contact portion 93 by the interval of the notch 92, the filter holder 71
Abuts against the contact portion 93 and moves in the sub-scanning direction with respect to the base 62, the movable bearing 85 engages with the notch 92 b, and the light emitting portion 65 of the fluorescent light emitting tube 63 has a green filter 64.
G is set. Thereafter, the print head is returned to the start position, and the print head is moved along the sub-scanning direction into the contact portion 93.
, The fluorescent light emitting tube 63 is driven by a drive signal corresponding to the green image, and the color film 61 is exposed by the green filter 64G.

After the exposure by the green filter 64G is completed, when the print head is further moved toward the contact portion 93 by twice the interval of the notch 92, the filter holder 71 abuts the contact portion 93 and the base 62 is contacted. , The movable bearing 85 is notched 92c.
And a blue filter 64B is set in the light emitting section 65 of the fluorescent light emitting tube 63. Thereafter, the print head is returned to the start position, and the fluorescent film 63 is driven by a drive signal corresponding to a blue image while moving the print head toward the contact portion 93 along the sub-scanning direction. Is exposed by the blue filter 64B. By the above operation, a full-color latent image is formed on the color film 61.

[0034]

However, in the conventional optical print head shown in FIG. 6, filters 59R, 59G and 59B are fixedly provided corresponding to the three lines of light emitting portions 55R, 55G and 55B. Although light of three primary colors is obtained, if the light emitting portions 55R, 55G, and 55B are close to each other, light enters the filter 59 of the adjacent light emitting portion 55 to cause color mixing.

For this reason, each of the light emitting sections 55R, 55G, 55
It is necessary to set the interval of B to such a size that color mixing does not occur, and there is a limit to shortening the interval of the light emitting portions 55 to reduce the size of the fluorescent light emitting tube 51. In addition, the distance between the light-emitting portions 55 is large, and the light from the light-emitting portions 55R, 55G, and 55B of three lines cannot be imaged by one lens system. Therefore, a lens system 60 must be provided for each line. ,
Also in this regard, there is a problem that downsizing is difficult and the manufacturing cost is high.

In the optical print head shown in FIGS. 7 to 10, in order to form a full-color latent image on a color film, a switching mechanism for selecting any one of red, green and blue filters is provided. It is indispensable and not only complicates the structure, but also causes mechanical wear when used for a long time. For this reason, there has been a problem that color unevenness and color shift occur in the latent image on the color film, and a desired latent image cannot be obtained, resulting in a lack of reliability. In addition, in order to form a full-color latent image on a color film, it is necessary to switch to each of the red, green, and blue filters, and to write three times in total for each of red, green, and blue in a time-division manner. There is a problem that writing time is required.

Accordingly, the present invention has been made in view of the above problems, and eliminates the need for a complicated configuration for switching filters, thereby improving mechanical reliability, and reducing the size by using a single lens system. It is an object of the present invention to provide an optical print head capable of simultaneously exposing red, green, and blue and shortening the exposure time.

[0038]

In order to achieve the above object, an optical print head according to the first aspect of the present invention comprises three lines of light emitting units R and R which can be divided into three primary colors of red, green and blue.
A light source 1 having G, B, one lens system 3 for condensing light from the light emitting units R, G, B on the surface of the object 21 to be written, and between the light source 1 and the lens system 3 And the light from each of the light emitting units R, G, B is adjusted by adjusting the optical distance between the light emitting units R, G, B of the three lines and the lens system 3 to the light of the lens system 3. An optical axis adjusting means 2 for inputting the light to the center of the axis;
The surface of the object 21 is exposed by scanning the surface of the object 21 by relative movement of the object.

The optical print head according to the second aspect of the present invention has three light emitting portions R, G, B of a single light emitting color.
And the light emitting units R, G, and B of the three lines, which are disposed on the emission surface side of the light emitting units R, G, and B of the three lines.
19R, 19G, and 19B for emitting light from the light source as three primary colors of red, green, and blue, and emitted from the light emitting units R, G, and B via the filters 19R, 19G, and 19B. One lens system 3 for condensing light on the surface of the object 21 to be written, and an optical path between the light source 1 and the lens system 3;
Optical axis adjusting means 2 for adjusting the optical distance between G, B and the lens system 3 so that light from each light emitting section R, G, B is incident on the center of the optical axis of the lens system 3; The surface of the object to be written 21 is scanned by scanning the surface of the object to be written 21 by relative movement between the light source 1 and the object to be written 21.

According to a third aspect of the present invention, in the optical print head according to the first or second aspect, the optical axis adjusting means 2 is configured to control the optical axis of one of the light emitting portions R, G, and B with the optical axis of the light emitting portion. One reflecting mirror 2B arranged at the intersection of the optical axes of the lens system 3
And the optical system of the lens system 3 is arranged at each intersection of the optical axis of the light emitting unit of the other two lines other than the light emitting unit in which the reflecting mirror 2B is arranged and the optical axis of the lens system 3. 3 and two dichroic mirrors 2Ca and 2Cb for transmitting the light incident from the reflecting mirror 2B to the lens system 3, and between the two dichroic mirrors 2Ca and 2Cb and the light emitting units of the two lines. The refractive index and the refractive index are set so that the optical distance between the two-line light emitting unit and the lens system 3 is equal to the optical distance of the one line light emitting unit where the reflecting mirror 2B is disposed. It is characterized by comprising two correction plates 2Aa and 2Ab made of a translucent member having a set thickness.

According to a fourth aspect of the present invention, in the optical print head according to the first or second aspect, the optical axis adjusting means is arranged at the same position on the optical axis of the two lines of the light emitting sections. Two reflecting mirrors, arranged at the intersection of the optical axis of the light emitting section of one line remaining in the light emitting section and the optical axis of the two reflecting mirrors, transmitting light from the light emitting section of the one line and the reflecting mirror Dichroic prism for reflecting light incident from the lens system on the lens system, and a two-line light-emitting unit disposed on an optical path between the dichroic prism and the one-line light-emitting unit, wherein the reflecting mirror is disposed. And one correction plate made of a light-transmitting member having a refractive index and a thickness set so as to match the optical distance.

According to a fifth aspect of the present invention, in the optical print head of the fourth aspect, the dichroic prism 22 is provided.
A reflecting mirror 22Bc for reflecting light from C to the center of the optical axis of the lens system 3 is disposed on an optical path between the dichroic prism 22C and the lens system 3.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical print head according to each of the embodiments described below is driven by a digital color image signal obtained from a video device, for example, and is used as a color video printer for printing a video image on a color film. Is done. In addition, electrophotographic printers,
It can be used for silver halide printers, level printers, etc.

FIG. 1 is a diagram showing a first embodiment of an optical print head according to the present invention, and FIG. 2 is a diagram showing an example of wiring connection of an anode conductor in the fluorescent tube of FIG.

The optical print head according to the first embodiment has a light source 1, an optical axis adjusting means 2, and a lens system 3. First, the configuration of the light source 1 will be described.

It should be noted that the light source 1 only needs to have a structure including three lines of light-emitting portions including red, green, and blue light-emitting components and divided into portions corresponding to the resolution. In addition, for example, an LED (light emitting diode), an organic electroluminescence element, or the like can be used.

As shown in FIGS. 1 and 2, the fluorescent light emitting tube 1 as a light source has an anode conductor 5 made of an aluminum thin film formed on an inner surface of a transparent substrate 4 made of glass. Wiring 10 for connection from each anode conductor 5 to the drive circuit
1 is provided. The anode conductors 5 are each driven one by one.
C can perform static driving. The light emitting units are provided in three sets of R, G, and B along the sub-scanning direction. Each of the anode conductors 5 has the same square-shaped through hole 6 formed therein. The anode conductor 5 and the through hole 6 can be obtained with high accuracy by forming a solid aluminum thin film by a sputtering method and patterning the thin film by a photographic method.

As shown in FIG. 1, a phosphor 7 is provided in each through-hole 6 by a photographic method, and a large number of luminescent dots 8 are formed. The phosphor 7 is, for example, Zn
O: Zn, which is common to the light emitting units R, G, B.

Since ZnO: Zn has a small resistance, sufficient electrical continuity with the anode conductor 5 can be obtained without mixing a conductive substance as long as the phosphor 7 is in contact with the inner peripheral wall of the through hole 6. . Further, the light emitting shape of the light emitting dot 8 matches the position and shape of the through hole 6 and the area is uniform for each light emitting dot 8, so that the same light amount can be obtained for each light emitting dot 8.

As shown in FIG. 1, an insulating layer 9 having a predetermined thickness is formed on the substrate 4 between the light emitting portions R, G, and B by screen printing. The control electrode 10 is provided on the insulating layer 9.
Is provided. The control electrode 10 is made by etching stainless steel and covers each light emitting dot 8.
The light emitting units R, G, and B may be provided independently for each of the light emitting units R, G, and B.

Above the control electrode 10, each light emitting unit R,
A linear cathode 16 is provided for each of G and B along the main scanning direction. On the upper surface of the substrate 4, a box-shaped container portion 17 composed of a side plate and a back plate is sealed, and an envelope 18 for storing various electrodes and the like is formed. The inside of the envelope 18 is evacuated to a high vacuum state. Although not shown, the back plate and the side plate are provided with a shielding film for blocking the invasion of external light and preventing flare.

As shown in FIG. 3 and FIG.
Are connected by the wiring 101, the control electrode 10 is connected to R, G, B
R, G, and B can be driven in a time-division manner by independently driving the matrix of the anode conductor 5 and the control electrode 10.

On the outer surface side of the substrate 4, a color separation filter 19 for passing a specific color out of the light output from the light emitting dots 8 is provided facing the light emitting portions R, G, B. Specifically, the color separation filter 19 includes a red filter 19R provided to face the light emitting unit R, a green filter 19G provided to face the light emitting unit G, and a blue filter provided to face the light emitting unit B. 19B. The light from each light emitting dot 8 of each light emitting unit R, G, B is red, green,
The light is emitted through the blue filters 19R, 19G, and 19B.

The lens system 3 is composed of, for example, a single Selfoc lens array, and each of the filters 19R, 19G,
19B is disposed at a position separated by a predetermined distance from the outer surface of the substrate 4 on which the 19B is disposed, in parallel with the outer surface of the substrate 4. Light from each light-emitting dot 8 of each light-emitting unit R, G, B enters the lens system 3 with respect to the center of the optical axis.

As shown in FIG. 1, the optical axis adjusting means 2
One correction plate 2A (2Aa, 2Ab), one reflecting mirror 2
B, two dichroic mirrors 2C (2Ca, 2C
b).

When the light incident on the above-mentioned lens system 3 deviates from the center of the optical axis, the level of the amount of light emitted from the lens system 3 decreases and the amount of uneven light increases. The light emitting dots 8 of the light emitting units R, G, B are so arranged that the light from R, G, B is incident on the center of the optical axis of the lens system 3.
The optical distance between the lens system 3 and the lens system 3 is matched.

The correction plate 2A is made of a translucent member. Specifically, it is composed of a glass plate such as quartz glass or soda-lime glass, or a resin plate such as acrylic, polystyrene, or polyvinyl chloride. The correction plate 2A is disposed on each of the emission surfaces of the green filter 19G and the blue filter 19B on the optical axis of the light emitting units G and B. The correction plate 2Aa has a refractive index such that the optical distance between each light emitting dot 8 of the light emitting unit G and the lens system 3 matches the optical distance between each light emitting dot 8 of the light emitting unit R and the lens system 3. And the thickness are set. Similarly, the correction plate 2Ab is provided between the light emitting dots 8 of the light emitting section B and the lens system 3.
The refractive index and the thickness are set so that the optical distance between the lens system 3 and the lens system 3 coincides with the optical distance between the light emitting dots 8 of the light emitting unit R and the lens system 3.

The reflecting mirror 2B is composed of, for example, a half mirror. The reflecting mirror 2B is located at a predetermined distance from the red filter 19R and the lens system 3 at a predetermined distance from the red filter 19R so that the center of the reflecting surface is positioned on the optical axis of the emission center of each emission dot 8 of the emission unit R. Are arranged at the intersection of the optical axes. This reflecting mirror 2B
The light that has passed through the red filter 19R from the light emitting dots 8 of the light emitting unit R is reflected toward the center of the optical axis of the lens system 3 (in the illustrated example, 90 ° clockwise).

The dichroic mirror 2C includes a thin film having a small refractive index and a thin film having a large refractive index on one side of the optical glass.
Approximately 0 layers are alternately stacked. The dichroic mirror 2C can transmit or reflect light in a specific wavelength range at an arbitrary light incident angle by controlling the thickness and the number of layers.

The dichroic mirror 2Ca is arranged at a predetermined distance from the green filter 19G so that its surface (transmission / reflection surface) is located on the optical axis of the emission center of each emission dot 8 of the emission portion G. Is arranged in parallel with the reflecting mirror 2B at the intersection of the optical axis of the lens system 3 and the optical axis of the lens system 3. In the dichroic mirror 2Ca, light passing through the green filter 19G from each light emitting dot 8 of the light emitting portion G is reflected toward the center of the optical axis of the lens system 3 (in the illustrated example, clockwise 90 °). . The light from the reflecting mirror 2B is transmitted toward the center of the optical axis of the lens system 3.

The dichroic mirror 2Cb is positioned at a predetermined distance from the blue filter 19B so that the surface of the dichroic mirror 2Cb is located on the optical axis of the emission center of each emission dot 8 of the emission section B. 3 is arranged in parallel with the reflecting mirror 2B and the dichroic mirror 2Ca at the intersection of the optical axes. In the dichroic mirror 2Cb, light that has passed through the blue filter 19B from each of the light emitting dots 8 of the light emitting section B is reflected toward the center of the optical axis of the lens system 3 (in the illustrated example, 90 ° clockwise). . The light from the reflecting mirror 2B and the light from the dichroic mirror 2Ca are transmitted toward the center of the optical axis of the lens system 3.

Here, the components constituting the optical axis adjusting means 2 are optically aligned so that the optical distance from each of the light emitting dots 8 of each of the light emitting portions R, G, and B to the lens system 3 matches. Be placed.

To describe the configuration of the first embodiment as an example, the distance between the light emitting dot of the light emitting unit B and the light emitting dot of the light emitting unit G is 1 mm, and the light emitting dot of the light emitting unit G and the light emitting unit B
The distance between the light emitting dots is 1 mm, and glass having a refractive index of 1.5 (the refractive index of soda-lime glass is 1.5
Since it is 1 to 1.52, it does not make much difference to use 1.5 for the calculation).

In order to make the optical distances of R, G and B coincide, the thickness of the correction plate 2Aa is 2 mm and the thickness of the correction plate 2Ab is 4 mm. The distance from the dichroic mirror 2Cb to the light emitting dot of the light emitting unit R is 1 + 1 + 4 + (red filter 19R + thickness of the substrate 4 of the fluorescent light emitting tube 1).

Therefore, a selfoc lens constituting the lens system 3 can be used if the focal length is 8 mm or more. Specifically, SLA6 (focal length 17 mm), SLA9 (focal length 10-19 mm), S
Selfoc lens arrays of the LA12 (focal length 9-15 mm) series can be used.

When driving the optical print head constructed as described above, the anode conductor 5 is statically driven while a positive signal (voltage) is applied to the control electrode 10 to emit light to be lit. A positive print signal (voltage) is applied to the anode conductor 5 of the portion. As a result, the light from each of the light-emitting dots 8 that are turned on is separated from the red, green, and blue filters 19R, 19R.
G, 19B, and through the optical axis adjusting means 2, the lens system 3
Is incident on.

That is, the light from each light emitting dot 8 of the light emitting section R passes through the two dichroic mirrors 2Ca and 2Cb after passing through the red filter 19R and is incident on the optical axis center of the lens system 3. Light from each light emitting dot 8 of the light emitting section G passes through the green filter 19G, is reflected by the dichroic mirror 2Ca, and is reflected by the dichroic mirror 2C.
b and is incident on the center of the optical axis of the lens system 3. Light from each light emitting dot 8 of the light emitting section B passes through the blue filter 19B, is reflected by the dichroic mirror 2Cb, and is incident on the optical axis center of the lens system 3.

The light incident on the lens system 3 is reflected 90 ° clockwise by the reflecting mirror 23, and is collected at a predetermined position on the color film 21 as the object to be written. The print head is aligned with this light emission drive in FIG.
Is moved at a constant speed in the sub-scanning direction indicated by the arrow M, the separated light of the same shape from the light emitting dots 8 of each color is collected at the same position, and a desired color image is formed on the color film 21. You.

FIG. 4 shows a second example of the optical print head.
It is a figure showing an embodiment. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The optical print head according to the second embodiment differs from the first embodiment in the configuration of a part of the fluorescent tube 1, the configuration of the optical axis adjusting means, and the arrangement position of the lens system 3. Others are the same.

The fluorescent tube 1 according to the second embodiment is
Control electrodes 10R, 10G, 1 independently for each light emitting unit R, G, B
0B, and a wiring connection structure in which the anode conductors 5 in the sub-scanning direction of the light emitting units R, G, and B are commonly connected as shown in FIG.

As shown in FIG. 4, the optical axis adjusting means 22 according to the second embodiment functions similarly to the optical axis adjusting means 2 according to the first embodiment. The reflecting mirror 22B (22Ba, 22Bb) includes one dichroic prism 22C.

The correction plate 22A is made of a light-transmissive member such as a glass plate or a resin plate having a large refractive index as in the first embodiment. The correction plate 22A is disposed on the emission surface side of the green filter 19G on the optical axis of the light emitting unit G. The refractive index and the thickness of the correction plate 22A are set so that the optical distances between the light emitting dots 8 of the light emitting units R, G, and B and the lens system 3 match.

The reflecting mirror 22B is constituted by, for example, a half mirror. The reflecting mirror 22Ba is provided for each light emitting dot 8 of the light emitting unit R.
So that the center of the reflection surface is located on the optical axis of the emission center of
A predetermined distance from the red filter 19R is provided at the intersection of the optical axis of the light emitting unit R and the optical axis of the incident surface of the dichroic prism 22C. The reflecting mirror 22Ba reflects the light that has passed through the red filter 19R from the light emitting dots 8 of the light emitting unit R toward the incident surface of the dichroic prism 22C (in the illustrated example, 90 ° clockwise).

The reflecting mirror 22Bb is arranged at a predetermined distance from the blue filter 19B so that the center of the reflecting surface is located on the optical axis of the light emission center of each light emitting dot 8 of the light emitting portion B. The dichroic prism 22C is disposed at the intersection of the incident surface and the optical axis. The reflecting mirror 22Bb is arranged symmetrically with respect to the reflecting mirror 22Ba with respect to the dichroic prism 22C. The reflecting mirror 22Bb reflects the light that has passed through the blue filter 19B from the light emitting dots 8 of the light emitting unit B toward the incident surface of the dichroic prism 22C (in the illustrated example, 90 ° counterclockwise).

The dichroic prism 22C is formed by coating two sides of a triangular prism having a right-angled isosceles cross section with a dichroic layer, and combining the four.

The dichroic prism 22C is positioned at a predetermined distance from the green filter 19G so as to be located on the optical axis of the light emission center of each light emitting dot 8 of the light emitting portion G and the two reflecting mirrors 22Ba and 22Ba. , 22Bb in parallel with the outer surface of the substrate 4 at the intersection with the optical axis. In addition, a lens system 3 is provided on the optical axis of the light emitting unit G on the emission surface side of the dichroic prism so as to face the green filter 19G.

In the dichroic prism 22 C, the light that has passed through the green filter 19 G from each of the light emitting dots 8 of the light emitting section G is transmitted straight through as it is and is incident on the optical axis center of the lens system 3. Further, the light from the reflecting mirror 22Ca is reflected (90 ° clockwise in the illustrated example) and is incident on the center of the optical axis of the lens system 3. Similarly, the reflecting mirror 22C
b is reflected (in the illustrated example, 90 ° counterclockwise).
°) to enter the center of the optical axis of the lens system 3.

The optical axis adjusting means 22 constructed as described above
Is adopted, the light from each light emitting dot 8 is red, green,
The light passes through the blue filters 19R, 19G, and 19B and enters the lens system 3 via the optical axis adjusting means 22.

That is, the light from each of the light emitting dots 8 of the light emitting section R passes through the red filter 19R, and then passes through the reflecting mirror 22B.
The light is reflected by a, and further reflected by the dichroic prism 22C, and is incident on the optical axis center of the lens system 3. Light emitting unit G
After passing through the green filter 19G, the light from each light emitting dot 8 passes through the dichroic prism 22C and is incident on the optical axis center of the lens system 3. The light from each light emitting dot 8 of the light emitting section B passes through the blue filter 19B, is reflected by the reflecting mirror 22Bb, and is further reflected by the dichroic prism 2B.
The light is reflected by 2C and enters the center of the optical axis of the lens system 3.

The light incident on the lens system 3 is collected by the lens system 3 at a predetermined position on the color film 21 as the object to be written. By moving the print head at a constant speed in the sub-scanning direction indicated by the arrow M in FIG. 6 in accordance with the light emission drive, the light of the same shape from the separated light emitting dots 8 of each color is collected at the same position, and Is formed on the color film 21.

FIG. 5 shows a third example of the optical print head.
It is a figure showing an embodiment. Note that the same components as those of the second embodiment are denoted by the same reference numerals, and description thereof will be omitted.

An optical print head according to the third embodiment shown in FIG. 5 has a reflecting mirror at the intersection of the optical axis center of the dichroic prism 22C and the optical axis center of the lens system 3 in addition to the configuration of the second embodiment. 22Bc are arranged.

In the third embodiment, the light emitted from the dichroic prism 22C is reflected by the reflecting mirror 22Bc (90 ° clockwise in the illustrated example) and enters the optical system 3. Other operations are the same as those of the second embodiment, and the light incident on the lens system 3 is reflected 90 ° clockwise by the reflecting mirror 23 through the center of the optical axis of the lens system 3 to be written. It is collected at a predetermined position on the color film 21 as a body.

As described above, according to the optical print head of each embodiment, light from each of the light emitting dots 8 of each of the light emitting units R, G, and B is transmitted from the correction plate, the reflecting mirror, the dichroic mirror, or the dichroic prism. The light is incident on one lens system by the constituted optical axis adjusting means.

Accordingly, simultaneous exposure of red, green, and blue can be performed, and a full-color latent image can be formed on a color film by shortening the exposure time. Moreover, FIGS.
Red, green, etc. like the conventional optical print head shown in FIG.
Since a mechanism for switching filters of each color of blue is unnecessary, there is no occurrence of color unevenness or color shift in a latent image on a color film due to mechanical wear of the filter switching mechanism, and sufficient mechanical reliability and image quality are obtained. Can be secured. Further, there is a restriction that a certain distance is provided between the light emitting units R, G, and B so as not to be affected by the adjacent light emitting units. However, since there is only one lens system, the conventional light emitting unit shown in FIG. The size can be reduced compared to the optical print head.

In the above-described embodiment, the print head is moved at a constant speed in the sub-scanning direction. Green and blue simultaneous exposure may be performed.

[0088]

As is apparent from the above description, according to the present invention, simultaneous exposure of red, green, and blue becomes possible, and a full-color latent image can be formed by shortening the exposure time.
Since the conventional filter switching mechanism is unnecessary, there is no possibility of causing color unevenness or color shift in the latent image on the color film due to mechanical wear of the filter switching mechanism,
It is possible to sufficiently secure mechanical reliability and image quality. Since only one lens system for condensing the light from the light emitting portion at a predetermined position on the color film is required, the size can be reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of an optical print head according to the present invention.

FIG. 2 is a diagram showing an example of wiring connection of an anode conductor in the fluorescent tube of FIG. 1;

FIG. 3 is a diagram showing another wiring connection example of the anode conductor in the fluorescent arc tube.

FIG. 4 is a diagram showing a second embodiment of the optical print head according to the present invention.

FIG. 5 is a diagram showing a third embodiment of the optical print head according to the present invention.

FIG. 6 is a diagram showing a configuration example of a conventional optical print head.

FIG. 7 is a diagram showing another configuration example of a conventional optical print head.

8A is a plan view of the optical print head of FIG. 7; FIG. 8B is a cross-sectional view taken along line AA of FIG.

FIG. 9 is a sectional view taken along line BB of FIG.

10A to 10C are plan views showing the configuration and operation of a print head in the optical print head of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source, 2, 22 ... Optical axis adjustment means, 2A, 22A ... Correction plate, 2B, 22B ... Reflection mirror, 2C ... Dichroic mirror, 3 ... Lens system, 19 ... Color separation filter, 19R ...
Red filter, 19G: green filter, 19B: blue filter, 21: object to be written, 22C: dichroic prism, R, G, B: light emitting unit.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2C162 AE28 FA16 FA17 FA19 FA36 FA45 FA49 FA58 FA67 5C051 AA02 CA10 DA02 DB02 DB22 DB24 DB28 DC02 DC04 DC07 DE19 DE27 DE31 EA01 5C072 AA03 BA03 BA19 CA04 CA07 DA02 DA05 DA06 DA09 DA10 DA20 DA21 DA23 XA04 5F041 EE11 EE22 EE23 EE25 FF13

Claims (5)

[Claims] 1. A light source having a light emitting portion of three lines that can be divided into three primary colors of red, green and blue, and a device for condensing light from the light emitting portion on a surface of an object to be written.
Three lens systems, disposed on an optical path between the light source and the lens system, and adjusting the optical distance between the three-line light emitting unit and the lens system to adjust the light from each light emitting unit to the lens system. Optical axis adjusting means for causing light to enter the center of the optical axis of the object, and by relative movement of the light source and the object to be written, the surface of the object to be written is scanned to perform surface exposure of the object to be written. An optical printhead that features. 2. A light source having three lines of light-emitting parts of a single light-emitting color, and disposed on the emission surface side of the three lines of light-emitting parts, and emitting light from the three lines of light from red, green, and blue. A filter for emitting light divided into three primary colors, a lens system for condensing light emitted from the light emitting unit through the filter on a surface of a writing object, the light source and the lens system Optical axis adjusting means disposed on an optical path between the light emitting unit and the optical line between the light emitting units of the three lines and the lens system so that light from each light emitting unit is incident on the optical axis center of the lens system. An optical print head, comprising: scanning the surface of the object to be subjected to surface exposure by relatively moving the light source and the object to be written. 3. The optical axis adjusting means includes one of the light emitting units.
One reflecting mirror disposed at the intersection of the optical axis of the light emitting portion of the line and the optical axis of the lens system; the optical axis of the light emitting portion of the other two lines other than the light emitting portion where the reflecting mirror is disposed; and the lens Two dichroic mirrors that are arranged at respective intersections of the optical axes of the system, reflect light from the light emitting unit to the lens system, and transmit light incident from the reflecting mirror to the lens system; The optical distance between the dichroic mirror and the two-line light-emitting unit is one, and the optical distance between the two-line light-emitting unit and the lens system is one-line light-emitting unit on which the reflecting mirror is arranged. 3. The optical print head according to claim 1, further comprising: two correction plates made of a translucent member having a refractive index and a thickness set so as to match the optical distance of the optical print head. 4. An optical axis adjusting means, comprising:
Two reflecting mirrors arranged at the same position on the optical axis of the light emitting portion of the line, and arranged at the intersection of the optical axis of the light emitting portion of the remaining one line of the light emitting portion and the optical axis of the two reflecting mirrors, One dichroic prism that transmits light from the one-line light emitting unit and reflects light incident from the reflecting mirror to the lens system; and on an optical path between the dichroic prism and the one-line light emitting unit. And a correction plate made of a light-transmitting member having a refractive index and a thickness set to match the optical distances of the two lines of light-emitting portions on which the reflecting mirror is disposed. 3. The optical print head according to 2. 5. The optical system according to claim 4, wherein a reflecting mirror for reflecting the light from the dichroic prism to the center of the optical axis of the lens system is disposed on an optical path between the dichroic prism and the lens system. Print head.