JP3396544B2 - Transmission original image recording device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent document image recording apparatus, and more particularly, to a transparent document capable of recording an image of a transparent document placed on a transparent document table. The present invention relates to an image recording device. 2. Description of the Related Art In recent years, an image recording apparatus capable of recording an image of a transparent original placed on a transparent original placing table has been put to practical use. In a conventional transmission original image recording apparatus, light emitted from a transmission exposure light source is scanned to transmit an original placed on an original mounting table, and the transmitted light is transmitted to the inside of the image recording apparatus main body. An image is recorded by guiding to an exposure unit. Typically,
In such a transmission original image recording apparatus, a light amount aperture is provided in an optical system, and the light amount aperture is adjusted to adjust the exposure amount. However, in the conventional transmissive original image recording apparatus, when scanning and exposing with the same light source, the exposure amount is controlled only by the light amount aperture. There is a problem that the exposure amount can be controlled only in the range (open range), and the density range of the transparent document that can be handled is limited. SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and an object of the present invention is to provide a transparent original image recording apparatus capable of expanding the density range of a transparent original. In order to achieve the above object, a first aspect of the present invention is a transparent original image recording apparatus capable of recording an image of a transparent original placed on a transparent original table. an apparatus comprising: transmitting exposure light source for scanning exposure of the document placed on the document table at a predetermined speed, the light amount diaphragm squeeze scanning exposure from the transparent exposure light source to a predetermined light quantity, the
Exposure amount calculation that calculates the exposure amount based on the density information of the transparent original
Calculating means, and the speed of scanning exposure by the light source for transmission exposure.
To a first speed or a second speed that is slower than the first speed
Speed control means for controlling and control by the speed control means
The light amount diaphragm according to the first speed or the second speed
Aperture area setting means for setting the aperture area, and the exposure amount
If the exposure calculated by the calculation means is less than the open value
The speed is controlled to the first speed by the speed control means.
And at the first speed by the aperture area setting means.
The aperture area is set to an appropriate aperture area, and the
If the calculated exposure is equal to or greater than the open value, the speed control
Control means to control the second speed.
Area setting means to reduce the drawing area according to the second speed.
And control means for controlling the setting . [0007] [act] According to the transparent original image recording apparatus according to claim 1, Toru
The exposure amount is calculated based on the density information of the excess document, and the first speed of the scanning exposure is reduced to the calculated exposure amount.
Set the area. Then, the original placed on the original placing table is scanned and exposed at the first speed by the transmission exposure light source. On the other hand, the calculated exposure amount is the first value of the scanning exposure.
If the light amount cannot be obtained even when the aperture stop is opened at the speed, the control means controls the second speed lower than the first speed.
Is controlled to set the aperture area corresponding to the second speed .
Then, the original placed on the original placing table is scanned and exposed at the second speed by the transmission exposure light source. As described above, according to the transparent original image recording apparatus of the present invention, since the scanning exposure speed can be set slow, the original density range in which proper exposure can be performed can be expanded. An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is an external perspective view of an image recording apparatus 10 to which the present invention is applied. As shown in FIG. 1, this image recording apparatus 10
A mounting table 12A for mounting a document on which an image is recorded is provided on the upper surface of the machine base 12. This listing 1
2A, a rectangular opening is provided and a transparent glass plate 45 is provided.
Is fitted. An operation panel 4 for operating the image recording apparatus 10 is provided on the upper surface of the machine base 12 of the image recording apparatus 10.
4 and a drive unit 300 for driving the transmission light source unit 350 is attached. The transmission light source unit 350 moves along a shaft 302 fixed in the drive unit 300. On the transparent glass plate 45, a transparent original 380 (FIG. 4)
After the transmission light source unit 350 is moved at a predetermined speed in a predetermined direction (direction of arrow A in FIG. 1) to a predetermined position, the transmission light source unit 350 moves in the opposite direction (direction opposite to the direction of arrow A in FIG. 1). When moving, transmission exposure is performed. After the transmission exposure is completed, the transmission light source unit 3
50 moves further in the opposite direction (the direction opposite to the direction of arrow A in FIG. 1) from the transmission exposure end position, and
A, 390B, and stops at the retracted position in FIG. On the other hand, at the time of reflection exposure, the transmission light source unit 350 is kept in a retracted state in the unit holders 390A and 390B so as not to interfere with the holding cover 400 used at the time of reflection exposure. . The holding cover 400 is attached to the machine base 12 by hinges 406 at two positions on the back side of the drive unit 300.
The support cover 408 is attached to a back cover support 408 located on the back side of the base. I have. For this reason, an original is set on the transparent glass plate 45 with the image surface facing downward, and the plate platen 410 is superimposed on the original, so that reflection exposure is possible. The drive unit 300 and the transmission light source unit 350 will be described in detail. As shown in FIG. 2, a stepping motor 308 for driving the transmission light source unit 350 is provided on the right side of the drive unit 300 (in the direction of arrow A).
And gear unit 3 for transmitting the power to pulley 310A
10 are arranged. This stepping motor 308
A substrate 306 is arranged on the side of.
Reference numeral 06 includes a driver circuit for supplying a drive pulse to the stepping motor 308 and the like. A bracket 314 is mounted on the left side of the drive unit 300.
The pulley 314A rotates on fourteen axes. An endless wire belt 312 is hung between the pulley 310A and the pulley 314A, and the power of the stepping motor 308 is transmitted to the endless wire belt 312. A part of the endless wire belt 312 is fixed to the transmission light source unit 350, whereby the transmission light source unit 350 moves in the direction of arrow A and in the opposite direction. A freely rotating pulley 358 is attached to a lower portion of the transmission light source unit 350, and the transmission light source unit 350 is supported on the machine base 12 by the pulley 358. On the other hand, the transmitted light source unit 350 is mounted on the top of the box-shaped housing 351 as shown in FIG.
A slit 357 for each fan unit 356 is provided. The transmission light source unit 35 shown in FIG.
The rear end of the wire belt 312 is fixed to a part of the wire belt 312 at a position (not shown) below the bracket 350A shown in FIG. 3 so as to receive a driving force. The shaft 302 penetrates the bracket 350A, and the transmission light source unit 350 slides along the shaft 302 by receiving the driving force of the stepping motor 308 via the wire belt 312, and reciprocates on the document table 12A. As shown in FIG. 2, inside the transmission light source unit 350, a transmission lamp 352 is mounted along one side of the document table 12A as a light source for performing transmission scanning exposure. Above the transmission lamp 352, symmetrical reflectors 354A and 354 that reflect the lamp light are provided.
B is mounted, and the upper portions of the two reflectors are opened to allow heat generated from the transmission lamp 352 to escape. A fan unit 356 is disposed above the reflectors 354A and 354B, and radiates heat generated from the transmission lamp 352 to the outside of the transmission light source unit 350. Next, referring to FIG.
The optical system will be described. As shown in FIG. 4, the light emitted from the transmission lamp 352 of the transmission light source unit 350 is reflected directly or on the reflectors 354A and 354B, transmitted through the transmission original 380 and the glass plate 45, and then guided to the slit plate 38B. You. The light that has passed through the slit plate 38 and that has been transmitted and scanned is subjected to a mirror unit 38C, an iris meter 52 (not shown in FIG. 4) as an actuator, an aperture 38E for adjusting the light amount, and a lens unit 38
D, the light reaches the exposure unit in the machine base 12 via the mirror unit 39 and a filter (not shown). The halogen lamp 38A, the slit plate 38B, and the mirror unit 38C are synchronized with the moving (scanning) speed of the transmission light source unit 350 by the power of an optical system drive motor 54 (see FIG. 6) described later. Moving. Here, the relationship between the exposure amount R, the aperture of the stop, and the scanning speed V of the transmission light source unit 350 will be described. First, the exposure amount R is obtained by the following equation. Exposure amount R = (light quantity × exposure time T) (1) When the density of the transmission original is high, it is necessary to increase this exposure amount so as to obtain proper exposure. . When the aperture is not open, the aperture may be further opened. However, when the aperture is open, the light amount (exposure amount) cannot be adjusted by the aperture alone. In this case, there is a method of increasing the amount of light. However, it is generally known that applying a high voltage to the transmission lamp causes a reduction in lamp life. Further, in the case of an electrophotographic image recording apparatus, there is a method of controlling the adhesion of toner to an electrostatic latent image by applying an electric force to toner by changing a developing bias potential. This has the side effect of blurring. Further, there is a method of adjusting one parameter when the other parameter reaches a limit by controlling the voltage of the transmission lamp and controlling the developing bias potential, but there is a problem in contrast. Therefore, while keeping the lamp life constant,
To increase the exposure amount R without blurring the solid image portion and lowering the contrast, it is necessary to change the exposure time T. In the present embodiment, the exposure time T is changed by changing the scanning speed V of the transmission light source unit 350,
The exposure amount R is adjusted by changing the opening degree (aperture area S) of 8E. FIG. 5 shows the relationship among the exposure amount R, the aperture area S, the scanning speed V, and the exposure time T. The horizontal axis represents the exposure time T, and the vertical axis represents the aperture area S of the aperture 38E. Has been taken. The vertical axis indicates the aperture area S _O when the aperture 38E is fully closed and the aperture area when the aperture 38E is fully open (at the time of opening).
The drawing area S _F is shown, and the drawing area S changes within the range from the drawing area S _O to the drawing area S _F. On the other hand, the transmission light source unit 35 in the normal mode
The scanning speed V ₂ of the scanning speed V ₁ and one stage slow mode of the transmission source unit 350 of 0 taken as in FIG. These scanning speeds V ₁ and V ₂ are constant speeds as described later. The exposure amount R ₁ when the aperture 38E is opened at the scanning speed V ₁ is represented by the area S _F AES _O by the above equation (1) since the brightness of the transmission lamp 352 is constant. Accordingly, the density information input by the operator from the operation panel 44 is calculated by a central processing unit (CPU) described later,
The area of the exposure amount R according to the calculation result (for example, the area S _C CD
If S _O ) is equal to or smaller than the area based on the exposure amount R _{1, the} stop area is set to S by the scanning speed V _{1 in the} normal mode.
Scanning exposure may be performed as _C. On the other hand, the area S _E KFS _O is equal to the area S _F AE
Equivalent to S _O. Therefore, the scanning speed V ₂ , the stop area S _E
It is possible to obtain an exposure amount R corresponding to the exposure amount R ₁ by a. Thus, as a result of calculating the concentration information by a CPU, a surface area of exposure R (e.g., the area S _A LGS _O) if is greater than the area of the exposure R _1, can not be properly performed exposure in the scanning speed V _1, Scanning speed V ₂ , aperture area S _A
Scanning exposure is performed. Next, the configuration of an electric circuit for performing proper exposure by the image processing apparatus 10 will be described. As shown in FIG. 6, inside the machine base 12,
A control circuit 50, an iris meter 52, an optical system drive motor 54, a halogen lamp 38A, and an exposure sensor 56 are provided. The control circuit 50 includes a central processing unit (C
PU) 51 (not shown), a drive circuit 52A (not shown) for driving the iris meter 52 by analog current control, and a driver circuit 5 for driving the optical system drive motor 54
4A (not shown) and a voltage circuit 46 (not shown) for supplying a predetermined voltage to the halogen lamp 38A are provided. The control circuit 50 is connected to an operation panel 44 for inputting the density and the like of a transparent original by an operator, and an exposure sensor 56 for detecting an exposure. The exposure sensor 56 is located in front of the exposure unit in the machine base 12. The control circuit 50 includes a driving unit 300
Is electrically connected to the control circuit 306A. The control circuit 306A includes the microcomputer 30
7 (not shown), a driver circuit 308A (not shown) for driving the stepping motor 308, the transmission lamp 352
Is provided with a voltage circuit 352A (not shown) for supplying a predetermined voltage. Further, the control circuit 306A is provided with a fan motor drive circuit 356A (not shown) for driving the fan motor 356 when the temperature detected by the temperature sensor 360 becomes equal to or higher than a predetermined temperature. Next, an exposure amount control routine of the CPU 51 provided in the control circuit 50 in the machine base 12 will be described with reference to FIG. In step 450, the process waits until a print key (not shown) on the operation panel 44 is pressed. When the print key is pressed, the process proceeds to the next step 452. In step 452, the operator reads the density of the transparent original set by a density adjustment setting button (not shown) on the operation panel 44. In the next step 454, step 452
The aperture degree of the aperture 38E (the above-described aperture area S) is calculated from the density of the transparent document read in step (1). Next, at step 456, it is determined whether or not the calculated value is equal to or larger than the open value (the size of the aperture area S is equal to the area S _F AE).
S _O above and whether it) is determined less than the opening value (area S _F AES _O when it is determined that less than the size) typically scanning exposure mode and aperture area S in step 460 Is set. On the other hand, if it is determined that the value is equal to or greater than the open value (the size of the area S _F AES _O ), in step 456, the scanning exposure mode and the aperture area S which are one step slower than the scanning exposure speed in the normal scanning exposure mode.
Is set. In this embodiment, the speed V ₁ of the transmission light source unit 350 in the normal scanning exposure mode is 50 mm.
/ Sec, and the speed V ₂ of the transmission light source unit in the scanning exposure mode one step slower is set to 33.3 mm / sec. In the next step 462, the subroutine of the scanning exposure process shown in FIG. 9 is executed, and the exposure amount control routine by the CPU 51 ends when the subroutine ends. As shown in FIG. 8, in step 470,
It is determined whether the setting of the operation panel 44 is transmission exposure or not. If a negative determination is made, another process is performed in step 472 (for example, a process of simultaneously turning on the halogen lamp 38A).
Is executed. On the other hand, if the determination is affirmative, step 47
In 2, the signal is output to the control circuit 306A. As a result, the microcomputer 307 of the control circuit 306A detects that the exposure is the transmission exposure, and turns on the transmission lamp 352 to turn on the transmission lamp 352 in FIG.
The transmission light source unit 350 is moved in the arrow A direction (details will be described later). In the next step 474, the CPU 51 outputs a signal to the driver circuit 54A and outputs the signal to the transmission light source unit 35.
The optical system drive motor 54 is driven in synchronization with the movement of 0, the exposure amount is detected by the exposure amount sensor 56, and a signal is output to the iris meter drive circuit 52A. As a result, FIG.
The aperture opening (aperture area S) calculated in step 454 is corrected according to the actual exposure amount (the iris meter 52 is controlled again), and a proper exposure state is achieved. In step 476, the driver circuit 54A
1 to drive the optical system drive motor 54 to perform scanning exposure in the direction opposite to the direction of arrow A in FIG. In the next step 478, the driver circuit 5
It is determined whether 4A has transmitted a predetermined number of pulses to the optical system drive motor 54. If not, step 476 is executed.
Move to. On the other hand, when it is sent (when the scanning exposure is completed), in the next step 480, the control circuit 3
06A and a driver circuit 54
A signal is output to A, and the optical system is returned to the predetermined transmission exposure start position by the optical system drive motor 54, and the subroutine ends. Next, an exposure amount control routine of the microcomputer 307 provided in the control circuit 306A will be described with reference to FIG. In step 490, the process waits until a mode signal is input from the control circuit 50 (step 47 in FIG. 8).
2), when a signal is input, the scanning exposure mode is detected in the next step 492. Next, at step 494, the driver circuit 3
A signal is output to 08A to drive the stepping motor 308 to move the transmission light source unit 350 in the direction of arrow A in FIG. At this time, as described above, the CPU 51
The opening degree (aperture area S) of 8E is corrected (see step 474 in FIG. 8). In the next step 496, the voltage circuit 352
A is output to turn on the transmission lamp 352, and a signal is output to the driver circuit 308A to drive the stepping motor 308 to scan and expose the transmission light source unit 350 in the direction opposite to the arrow A direction in FIG. Next, in step 498, it is determined whether or not a stop signal has been input from the CPU 51. If a negative determination is made, the process proceeds to step 496. On the other hand, when the determination is affirmative, in the next step 500, the power supply circuit 35
2A and a signal to the driver circuit 308A to turn off the transmission lamp 352, and the unit holders 390A and 39
After moving to the retreat position stored in 0B, the processing routine ends. As described above, according to the image processing apparatus of this embodiment, since the speed of the transmission light source unit 350 and the stop 38E can be controlled, it is possible to perform proper exposure even when the stop 38E is opened. The effect can be obtained. In this embodiment, the scanning speed V of the transmission light source unit is set to two levels, that is, the normal mode and the mode one step slower. However, as is clear from the above, even if the aperture is opened in the mode one step slower. By setting a slower scanning speed and an aperture area at that time, proper exposure can be performed even on a transparent original having an extremely high density. As described above, according to the first aspect of the present invention, since the scanning exposure speed can be set slow, the original density range in which proper exposure can be performed can be expanded. Obtainable.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of an image recording apparatus according to the present embodiment. FIG. 2 is a diagram showing a schematic configuration of a drive unit according to the embodiment.
FIG. 2 is a sectional view taken along line II-II of FIG. FIG. 3 is a plan view of FIG. 2 showing a transmission light source unit of the present embodiment. FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 1, illustrating an outline of an optical system during transmission exposure according to the present embodiment. FIG. 5 is a diagram illustrating a relationship among an exposure amount, an aperture area, a scanning speed, and an exposure time. FIG. 6 is a block diagram of exposure amount control of the image recording apparatus of the present embodiment. FIG. 7 is a flowchart showing an operation of the CPU 51 of the control circuit 50; FIG. 8 is a flowchart showing a subroutine of step 462 in FIG. 7; FIG. 9 is a flowchart showing an operation of the microcomputer 307 of the control circuit 306A. [Description of Signs] 10 Image recording device 38E Aperture (aperture stop) 51 CPU (control means) 300 Drive unit 307 Microcomputer (control means) 350 Transmission light source unit 352 Transmission lamp (light source for transmission exposure)

Claims (1)

(1) A transparent document image recording apparatus capable of recording an image of a transparent document placed on a transparent document table, wherein the image is recorded on the document table. A transmission exposure light source for scanning and exposing the scanned document at a predetermined speed, a light amount aperture for reducing the scanning exposure from the transmission exposure light source to a predetermined light amount, and an exposure for calculating an exposure amount based on density information of the transmission document.
The amount of the scanning exposure by the quantity calculating means and the transmission light source is set to a first speed.
Degree, or a speed to control to a second speed lower than the first speed
Control means, a first speed or a second speed controlled by the speed control means.
Diaphragm that sets the diaphragm area of the light amount diaphragm according to the speed of the diaphragm
The exposure amount calculated by the area setting means and the exposure amount calculating means becomes an open value.
If not, the first speed is controlled by the speed control means.
And the aperture area setting means sets
1 to set the aperture area according to the speed.
If the exposure calculated by the calculation means is equal to or greater than the open value,
When the second speed is controlled by the speed control means,
In addition, the throttle area setting means adjusts the speed according to the second speed.
And a control unit configured to control the aperture area to be set .