JPH04189062A - Picture exposing device - Google Patents

Abstract

PURPOSE:To generate a picture without density and color unevenness by revising exposure information of an optical beam corresponding to picture information in response to a measured temperature of a photosensing material and controlling the exposure of the light beam based on the revised exposure information. CONSTITUTION:The temperature of a photosensing material 36 is measured by a temperature sensor 46 and inputted to a control circuit 12 via an ADC 48. The circuit 12 converts the measured temperature of the material 36 into exposure information of a laser beam. The converted exposure information is inputted to each driver 58 and laser beams L1, L2, L3 of a prescribed exposure radiate from the semiconductor laser 14 by driving the relevant semiconductor laser 14. The beams L1, L2, L3 radiating from the laser 14 are mixed through an optical path 24 and the result radiates to the material 36 via reflection mirrors 26,28, a polygon mirror 30, an ftheta lens 32 and a cylindrical mirror 34. Thus, the laser beam with the exposure in response to the measured temperature radiates to the photosensing material, a prescribed coloring density is obtained and a desired picture is formed.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to an image exposure apparatus, and particularly an image exposure apparatus that records an image by exposing a photosensitive material to a light beam containing a plurality of wavelengths. Regarding.

[Prior art]

2. Description of the Related Art Conventionally, image exposure apparatuses such as laser beam printers have been known that record images by exposing a photosensitive material to a light beam that is a mixture of a plurality of laser beams having different wavelengths. This image exposure device has a polygon mirror (
A rotating polygon mirror) is provided, and a light beam is irradiated onto a reflective surface provided on the polygon mirror, and main scanning of the light beam is performed by rotating the polygon mirror. Further, sub-scanning is performed by moving the photosensitive material. In this way, a two-dimensional image is recorded on the photosensitive material by performing main scanning and sub-scanning of the light beam.

Note that sub-scanning may be performed by irradiating the light beam reflected from the polygon mirror onto the photosensitive material via a deflector and deflecting the light beam in the sub-scanning direction by the deflector.

[Problem to be solved by the invention]

As the photosensitive material, for example, a heat-developable photosensitive material is used. Further, for general photosensitive materials including this heat-developable photosensitive material, the amount of exposure necessary for the color density to be obtained is determined. However, even if a photosensitive material is properly exposed to light in order to obtain a desired color density, it may not be possible to obtain a predetermined color density depending on the temperature of the photosensitive material. That is, in the above-mentioned photosensitive material, there is a tendency that the color density decreases as the temperature of the photosensitive material increases. As a result, the color density of the photosensitive material corresponding to the amount of exposure depends on the temperature of the photosensitive material at the time of exposure, resulting in uneven density and color in the resulting image. In addition, especially when the photosensitive material is sensitive to infrared light, the color density of the photosensitive material corresponding to the amount of exposure is highly dependent on the temperature at the time of exposure, and if exposure is performed at a high temperature, the color density becomes even more There is a problem in that a further exposure amount is required to obtain a proper coloring state.

Although it is possible to set an allowable temperature range and use the image exposure device within that range, it is not suitable for environments or areas where temperature changes are large, and the operating temperature range is limited. Therefore, practicality is impaired, which is not preferable.

The present invention was made to solve the above problems, and an object of the present invention is to provide an image exposure apparatus that can obtain stable image quality over a wide temperature range.

[Means to solve the problem]

In order to achieve the above object, the invention described in claim (1) provides a temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam; a converting means for converting density information into light beam exposure information and outputting it; an exposure control means for controlling the exposure amount of the light beam based on the exposure amount information; and a temperature measured by the temperature sensor. and a changing means for changing the exposure amount information according to the exposure amount information.

The invention described in claim (2) also provides a temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam, and a temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam, and a a converting means that stores tables each representing a relationship with the beam exposure amount information according to the temperature of the photosensitive material, converts the density information into exposure amount information by referring to the selected table, and outputs the converted information; The apparatus includes an exposure amount control means for controlling the exposure amount of the light beam based on exposure amount information, and a selection means for selecting a table of the conversion means according to the measured temperature of the photosensitive material.

Further, the invention described in claim (3) provides a temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam, and a temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam, a converting means that stores a table representing a relationship with the exposure amount information of the beam and converts the density information into exposure amount information by referring to the table and outputs the converted information; and exposure of the light beam based on the exposure amount information. The exposure amount control means for controlling the exposure amount, and the rewriting means for rewriting the exposure amount information according to the measured temperature of the photosensitive material are provided.

[Effect]

The temperature sensor of the invention described in claim (1) directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam. The converting means converts the density information of the image to be recorded on the photosensitive material into exposure amount information of the light beam and outputs it, and also converts the exposure amount information corresponding to the density information according to the temperature of the photosensitive material measured by the temperature sensor. change.

Then, the exposure amount control means controls the exposure amount of the light beam based on this exposure amount information. In this way, the exposure amount information of the light beam corresponding to the density information of the image is changed according to the measured temperature of the photosensitive material, and the exposure amount of the light beam is controlled based on the changed exposure amount information. Therefore, the relationship between the density information of the image and the exposure amount of the light beam is a relationship that depends on the temperature of the photosensitive material.

Therefore, by irradiating the photosensitive material with a light beam with an exposure amount obtained based on the exposure amount information changed according to the temperature of the photosensitive material, the desired color density can be obtained on the photosensitive material. An image without density unevenness or color unevenness can be formed on a photosensitive material regardless of temperature.

The temperature sensor of the invention described in claim (2) measures the temperature of a photosensitive material directly or indirectly.

The selection means selects a table of conversion means according to the temperature of the photosensitive material measured by the temperature sensor. The converting means stores tables representing the relationship between the density information of the image to be recorded on the photosensitive material and the exposure amount information of the light beam according to the temperature of the photosensitive material, and converts the photosensitive material by referring to the table selected by the selecting means. The density information of the image recorded on the material is converted into light beam exposure amount information and output. Then, the exposure amount control means controls the exposure amount of the light beam based on the exposure amount information. In this way, a table representing the relationship according to the measurement temperature of the photosensitive material is selected, and by referring to this selected table and converting the density information of the image into the exposure amount information of the light beam, the photosensitive material can be measured. Information on the exposure amount of the light beam is obtained according to the temperature, and the exposure amount of the light beam is controlled based on this information on the exposure amount of the light beam. Therefore, the relationship between the density information of the image and the exposure amount of the light beam is a relationship that depends on the temperature of the photosensitive material. Therefore, by irradiating the photosensitive material with a light beam having an exposure amount based on exposure amount information obtained by referring to a table selected according to the temperature of the photosensitive material, the desired color density can be obtained on the photosensitive material. Accordingly, an image without density unevenness and color unevenness can be formed on the photosensitive material regardless of the temperature of the photosensitive material.

The conversion means of the invention described in claim (3) stores a table representing the relationship between density information of an image to be recorded on a photosensitive material and exposure amount information of a light beam, and converts the photosensitive material by referring to this table. The rewriting means converts and outputs density information of an image to be recorded on the material into light beam exposure amount information and rewrites the light beam exposure amount information in accordance with the temperature of the photosensitive material measured by the temperature sensor. The exposure amount control means controls the exposure amount of the light beam based on the exposure amount information. In this way, the light beam exposure amount information corresponding to the image density information is rewritten according to the measured temperature of the photosensitive material, and the light beam exposure amount information that corresponds to the image density information is rewritten according to the measured temperature of the photosensitive material. The beam exposure amount is controlled. Therefore, the relationship between the density information of the image and the exposure amount of the light beam is determined according to the temperature of the photosensitive material. Therefore, by irradiating the photosensitive material with a light beam with an exposure amount obtained based on the exposure amount information rewritten according to the temperature of the photosensitive material, the desired color density can be obtained on the photosensitive material. An image without density unevenness or color unevenness can be formed on a photosensitive material regardless of temperature.

[Effects of the Invention As explained above, according to the present invention, a desired color density can be obtained regardless of the temperature of the photosensitive material during exposure, and an image with less density unevenness and color unevenness can be obtained. There is an effect.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 3 shows an image exposure apparatus to which the present invention is applied.

This image exposure apparatus 10 includes semiconductor lasers 14a and 14b.
and 14C. This semiconductor laser] 4a, 1
4b and 14C are driven by drivers 58a, 58b, and 58c as exposure amount control means, and the semiconductor laser 14a outputs an infrared laser beam L1 having a wavelength of, for example, 810 nm, and the semiconductor lasers 14b and 14
c outputs laser beams L2 and L3 having wavelengths of, for example, 750 nm and 670 nm, respectively. Further, the wavelengths of the laser beams L1, L2, and L3 correspond to the colors of red, green, and blue that are produced when the photosensitive material is exposed to light. Note that the semiconductor laser 14 that outputs the laser beams L1, L2, and L3 having these wavelengths can be produced very easily by hand.

A collimator lens 16a that converts the laser beam L1 into a parallel beam is disposed on the laser beam emission side of the semiconductor laser 14a, and a cylindrical lens 18a and a reflecting mirror 2 are arranged at a predetermined distance from the collimator lens 16a.
0 is provided. Similarly, collimator lenses 16b and 15c are provided on the laser beam emission sides of the semiconductor lasers 14b and 14C, respectively.
Cylindrical lenses 18b and 18C are provided at a predetermined distance from lenses 6b and 16c.

A guichroic mirror 2 is placed on the optical path of the laser beams L2 and L3 passing through the cylindrical lenses 18b and 18C.
22, 22b are provided.

Reflection mirror 20 and Gikroic mirror 22312H)
have the same inclination angle, and each laser beam L1,
L2 and L3 are guided into the same optical path 24. The guichroic mirror 222 transmits the laser beam L1 and also deflects the laser beam L2. On the other hand, the guichroic mirror 22b has a function of transmitting the laser beams L1 and L2 and reflecting the laser beam L3.

Laser beams L1, L2, and L that have reached the same optical path 24
3 is reflected by reflection mirrors 26 and 28, and then enters polygon mirror 30. The polygon mirror 30 rotates in the direction of the arrow, and the laser beams L1, L2, and L3 reflected by the polygon mirror 30 pass through the fθ lens 32 and pass through the cylindrical mirror 34 for surface tilt correction.
The beam is reflected by the beam and main-scanned over the photosensitive material in the six directions indicated by the arrows.

The photosensitive material 36 is conveyed in the sub-scanning direction (direction of arrow B) substantially perpendicular to the main-scanning direction by driving the conveyance roller 72 shown in FIG. 6(1) by a sub-scanning means (not shown). As a result, an image is formed on the photosensitive material 36.

Further, a temperature sensor 46 connected to the ADC 48 is arranged below the photosensitive material 36, and the temperature sensor 46 has the following characteristics:
For example, a thermocouple or the like is used. The ADC 48 is connected to the control circuit 12, and the control circuit 12
Connected to a153b and 58C.

As shown in FIG. 1, the control circuit 12 includes a CPU (central processing unit) 50. ROM (read only memory) 52 and RAM (random access memory) 54
A path line 44 is connected to each unit so that data, commands, etc. can be input/output between them. Further, a host computer 70 is connected to this lot line 44, and human power such as data and commands are performed. On the other hand, as shown in FIG. 6(1), a temperature sensor 46 is disposed at a position where it can directly measure the temperature of the photosensitive material 36.
(digital converter) 48. This ADC4
8 and converting means 80a, 80b, 80C are connected to the pass line 44.

The conversion means 80a includes a register 82aSDΔC34a and tables (r) 92a, 92b, and 92C. The converting means 80b and 80c also have a similar configuration. This table (r) (hereinafter referred to as LUT(r)) represents the relationship between image density information and laser beam exposure amount information, and for example, outputs the exposure amount information of the semiconductor laser 14a corresponding to red coloring. The converting means 80a converts three types of LUT(r) 92a, 92b, and 92 in accordance with the temperature of the photosensitive material.
Equipped with 2C.

Further, conversion means 80b and 80 corresponding to green and blue color development
c also has similar tables (g) and (b) (hereinafter referred to as LUT (g
) and LUT(b)). That is, the temperature of the photosensitive material is divided in advance into a plurality of temperature ranges, and one of the divided temperature ranges is
Prepare tables for different temperature ranges. For example, in this embodiment, the temperature T of the photosensitive material of the image exposure device 10 is
between 0°C and 50°C, 0°C≦T<20
6C, 20°C≦T<30°C and 30°C≦T≦50
It is divided into three temperature ranges: 'C. The table is 0
LUT(r)9 in the temperature range of °C≦T〈20°C
2a, LU in the temperature range of 20°C≦T<30°C
LUT(r) 92C is used in the temperature range T(r) 92 b and 30°C≦T≦50°C. Similarly, in the conversion means 80b that outputs the light amount information of the semiconductor laser 14b(7), LUT(g) 94a is used in the temperature range of 0°C≦T<20°C, and the temperature of 20°C≦T<30°C. LUT(g)94b and 30°051 in the range
L U T (g) 9 in a temperature range of 550°C
4C is used, and in the conversion means 80C that outputs the exposure amount of the semiconductor laser 14C, LUT (b) 96 a, 20''C≦T<30 in the temperature range of 0°C≦T<20°C.
LL'T et al.] 96b and 30° in the temperature range of °C
LUT(b)96 in the temperature range C≦T≦50°C
c is used.

The operation of this embodiment will be explained below.

The density information of the image supplied from the host computer 70 is supplied to the data area of the RAM 54, and the temperature of the photosensitive material 36 is measured by the temperature sensor 46.
48 to the data area of the RAM 54. The density information of this image is determined by the measured temperature of the photosensitive material 36.
According to a control routine described below, the information is converted into laser beam exposure amount information according to the measured temperature of the photosensitive material 36.

This converted exposure amount information is input to each dry no. \-58, and the corresponding semiconductor laser 14 is driven to produce laser beams L1, L2, and L with a predetermined exposure amount.
3 is emitted from the semiconductor laser 14. Semiconductor laser 1
Each laser beam L1, L2, L3 emitted from 4
are mixed into the optical path 24 and irradiated onto the photosensitive material 36 via the reflecting mirrors 26 and 28, the polygon mirror 30, the fθ lens 32, and the cylindrical mirror 34. As a result, the photosensitive material is irradiated with a laser beam with an exposure amount corresponding to the measured temperature, and a desired color density is obtained, thereby forming a desired image.

Here, the control routine of this embodiment will be explained in detail with reference to FIG. When image recording is started, in step 120, C is set to 1, and a value corresponding to the color sensitive layer of the photosensitive material 36 on which image density information is to be recorded is set. The value set for this C corresponds to the color produced by the photosensitive material, and the values are set as 1 for red, 2 for green, and 3 for blue. In step 122, the density information J of the image and the temperature t of the photosensitive material are taken in, and in step 124
Then, the temperature range Hn (
n=1.2.3). That is, the temperature t of the photosensitive material is Hl in the temperature range of 0°C to 20°C with a center temperature of 10°C, and 20°C with a center temperature of 25°C.
A temperature range of ~30°C is classified as H2, and a temperature range of 30°0 to 50°C with a center temperature of 40°C is classified as H3.

In step 126, a table (LUT) prepared corresponding to the temperature range Hn is selected, and the selected LUT
Based on this, in step 128, the image density information J is converted into laser beam exposure amount information, that is, a laser drive value, and is stored in the register 82a. Step 13
0, it is determined whether or not it is C20, and it is determined whether all the colors produced by the photosensitive material have been completed.If they have been completed, the process proceeds to step 132, and if there are still colors to be recorded, In step 121, the value of C is incremented by 1, and the process returns to step 122, where the density information of the laser beam of the next color is converted into exposure amount information. As a result, the density information j of the image is converted into a laser drive value in the same manner as above in the order of green and blue, and is stored in the registers 82b and 82C. In step 132, registers 82a, 82b
All the lasers are simultaneously driven according to the laser drive value j stored in each of the photosensitive materials 82c and 82c, and the photosensitive material is exposed to laser beams L1, L2, and L3 with an exposure amount corresponding to the temperature of the photosensitive material, and the process proceeds to step 134. , it is determined whether all images have been recorded on the photosensitive material. If the recording has not been completed, the process returns to step 120 to proceed to the next recording control.

The table will be explained with reference to FIGS. 4 and 5. In the photosensitive material 36, as shown in FIG. Put it away. As a result, even if exposure is performed to obtain the desired color density, the color density varies depending on the temperature of the photosensitive material 36, making it impossible to obtain the desired image.

Therefore, the temperature of the photosensitive material 36 is divided into allowable temperature ranges in which the color density changes little, and a table is prepared for the divided temperature ranges. That is, as shown in FIG. 5, characteristics of laser beam exposure amount information corresponding to image density information are prepared according to the temperature range of the photosensitive material 36, and these characteristics are used as a table.

Note that in this example, the temperature range is divided into three depending on the measured temperature of the photosensitive material, and a table corresponding to the divided temperature range is used. However, this temperature range is limited to three ranges. Instead, tables set for each measured temperature, further subdivided temperature ranges, and temperature ranges based on combinations thereof may be used.

Furthermore, in this embodiment, the case where a table is selected according to the measured temperature of the photosensitive material has been described, but a plurality of temperatures (for example, 10
By interpolating or other calculations (for example, interpolating the characteristics at 10°C and 25°C), the exposure characteristics suitable for the measurement temperature (e.g., 20'C) The contents of the table to be used may be rewritten by calculating this value. Alternatively, one reference table may be prepared in advance, and the contents of the table may be rewritten by using the deviation from the reference table for the exposure amount corresponding to the measured temperature of the photosensitive material.

Next, as shown in FIG. 6(2), an embodiment in which the temperature is measured indirectly by measuring the temperature around the photosensitive material 36 will be described. In this embodiment, the temperature of at least one force point or higher is measured near the insertion and ejection guide of the photosensitive material 36, the conveyance roller 72, the exposure section, and the like. The temperature of the photosensitive material 36 is estimated from the measured ambient temperature. By preparing a table representing the relationship between image density information and light beam exposure amount information according to the estimated temperature of the photosensitive material, the light beam exposure amount can be calculated using the same method as in the above embodiment. can be controlled. This embodiment is effective when the ambient temperature has a large influence on the photosensitive material 36 or when the temperature of the photosensitive material 36 cannot be measured directly.

In the above embodiment, visible light and infrared light are used to form a light beam, but the invention is not limited to this, and only visible light and infrared light may be used. . Further, the photosensitive material may be one that develops a visible color with visible light, one that develops a visible color with non-visible light (infrared photoacid 5) or ultraviolet light, or a combination thereof.

In the above embodiment, a case was explained in which an image is formed using three semiconductor lasers, but the light beam generating element is not limited to semiconductor lasers, and may include gas lasers, LEDs, and other light emitting devices. Elements may also be used,
Further, the number to be used is not limited to three, and may be changed.

In the above embodiment, the case where an image is recorded as an image exposure device has been explained, but a reading and reproducing device that obtains image information using a photoelectric conversion element etc. can also use the spectral absorption characteristics of the medium on which the image is recorded on the table. It can be easily adapted by adjusting temperature, etc.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the contents of the control circuit, Fig. 2 is a flow chart showing the contents of the control circuit, Fig. 3 is an image exposure apparatus to which the present invention can be applied, and Fig. 4 shows the exposure amount versus temperature of the photosensitive material. FIG. 5 is a diagram showing an example of the relationship between image density information and laser drive current. FIG. 6 (1) is a diagram showing an example of the relationship between image density information and laser drive current. FIG. 6(2) is a perspective view showing the periphery of the photosensitive material in another embodiment. 10... Image exposure device 12... Control circuit 1.4a, 14b, 14c... Semiconductor laser 46... Temperature sensor

Claims (3)

[Claims] (1) A temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam, and a temperature sensor that converts density information of the image recorded on the photosensitive material into light beam exposure amount information and outputs the information. A conversion device, an exposure amount control device that controls the exposure amount of the light beam based on the exposure amount information, and a changing device that changes the exposure amount information according to the temperature measured by the temperature sensor. image exposure equipment. (2) A temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam, and a table representing the relationship between the density information of the image recorded on the photosensitive material and the exposure amount information of the light beam. a converting means that stores the density information according to the temperature of the photosensitive material and converts the density information into exposure amount information by referring to the selected table and outputs the exposure amount information;
An image exposure apparatus comprising: an exposure amount control means for controlling the exposure amount of the light beam based on the exposure amount information; and a selection means for selecting a table of the conversion means according to a measured temperature of the photosensitive material. (3) A temperature sensor that directly or indirectly measures the temperature of a photosensitive material on which an image is recorded by a light beam, and a table representing the relationship between the density information of the image recorded on the photosensitive material and the exposure amount information of the light beam. a conversion means for storing the density information and converting the density information into exposure amount information by referring to the table and outputting the same; an exposure amount control means for controlling the exposure amount of the light beam based on the exposure amount information; An image exposure apparatus comprising: rewriting means for rewriting the exposure amount information according to a measured temperature of a material.